Ahhh, ok I get that since it is right before the midsummer solstice. I wish that there had been a connection between that date/memory and when Harry realized the significance of the solstice when talking to the Mothers. That would have closed the circle nicely. To a casual observer or someone who is unaware of dates (like me) it looks like an unfulfilled thread. Thank you.

Here are some relevant quotes from SK. First from when Harry is questioning the Mothers.

I held up a hand. "Hold it, hold it. Look, as I understand it, this power of the Summer Knight, his mantle, it can't just exist on its own. It has to be inside a vessel."
"Yes," Winter murmured. "Within one of the Queens, or within the Knight."

Then a few paragraphs later:

"How does the mantle pass on from one Knight to the next?"
Mother Summer smiled, but the expression was a grim one. "It returns to the nearest reflection of itself. To the nearest vessel of Summer. She, in turn, chooses the next Knight."

I know that these specifically refer to Summer, but for the sake of argument and in absence of other evidence I am going to proceed with the notion that the same applies to Winter. From these quotes we can glean a few things. Number 1, the mantles return to the nearest Queen. Number 2, that Queen then bestows the mantle onto the knight. Number 3, Mother Summer makes no mention of the previous knight having to die for the mantle to be released. I personally believe that there is a way for the Queens to take the mantle from a knight without requiring his or her death. Finally, no mention is made of needing the stone table for the transfer of the mantle. This is further corroborated by the fact that Fix was made the Summer Knight after the Stone Table was in possession of Winter. Also corroborated by logic because if the stone table was needed then the potential exists for the Knight mantle to be stuck within a Queen for months while they waited for the stone table to come back into their possession. This would result in an imbalance between the courts since one side does not have a Knight exerting their power.

Therefore, if we accept that the Knights Mantle could have been removed at any time and held by Mab and then bestowed onto Harry at a time of his choosing, why did she keep Slate alive (besides revenge) and utilize the stone table? My theory stems from two more quotes from a conversation in SK between Lea and Harry.

I shook my fingers and looked at my godmother. "Let me get this straight. Blood spilled onto the Table turns into power for whoever holds it. Summer now. But Winter, after tomorrow night."

Followed by:

She frowned at the Table, then began pacing around it, slowly, clockwise, her eyes never leaving me. "The Table is not merely a repository for energy, child. It is a conduit. Blood spilled upon its surface takes more than merely life with it."
"Power," I said. I frowned and folded my arms, watching her. "So if, for instance, a wizard's blood spilled there ..."
She smiled. "Great power would come of it. Mortal life, mortal magic, drawn into the hands of whichever Queen ruled the Table."

My theory is twofold (because Mab never does just one thing when she can accomplish more). First, Mab did not want to just pass the same mantle onto Harry. She wanted to purify or slightly change it. By killing Slate on the table the mantle was transferred to Winter as power. Mab then took that pure power (possibly without the taint of Slate or Maeve) and gave it to Harry as the Knight mantle. Second, killing the mortal on the table also yielded some additional power. Not as much as killing Harry or another wizard, but I am guessing that their was a power gain regardless. If this was then added to the Mantle during the transfer it could possibly give Harry an additional power boost to make him greater then Summer and better able to face what is coming.

Wow, this is a pretty deep thread. Count me in the "letting the world burn" category when it comes to saving my child. I bear no animosity towards Dresden for saying that. It does not cheapen his character in my eyes. As Mira says, the important thing is that Harry saved his daughter in the most efficient way possible. It did have unintended consequences with regards to the Fomer, but the war was never going to end cleanly no matter which side won.

As for Deirdre, she and Nic are clearly in the end justify the means camp. They sought to save the world by changing the world into one after their own image. Within the Nickelhead camp she will probably go into the books as a savior figure or martyr depending on who you ask. From the outside she will be regarded as a tragedy. Someone who spent their whole life within that "society" and had no real chance to choose a different path. Is it really a sacrifice if the choice is not really a choice at all?

Didn't someone say in the books that the stone table was specifically created to funnel power between the courts through the spilling of blood? I do not think that is the islands purpose. A lot of beings were killed there during the events of turncoat and no mention was made of any type of power-up.

As I understand it (and someone correct me if I am wrong), if Mab dies and Molly moves up she would inherit Mab's mantle, yet still hold the Winter Lady mantle until she can choose someone to replace her. That means it is completely Molly's choice who would replace her. At this point I do not think we have been introduced to a character who fits really well. Murphy, Justine, and Andi could because they have not had children yet, but all are in serious relationships at this time. Here is a longshot: how about Faith. WoJ states that she has a role to play in the BAT. Maybe she steps in as the new Winter Lady.

I always pictured her as having a rapier, but that could be because that is what she ended that book with.

I think the novelty of the lightsaber will keep him alive initially. Hopefully long enough for his training to make him something greater.

Can a WCV become Fae? What do you think of the idea that every supernatural being: Fae, dragons, vampires, gods, werewolves, and Fomor are actually rooted in Outsiders that have been altered by our reality and diluted by time and generations? It is just a notion I have been toying with.

We know that Thomas could take up the Winter Knight Mantle because Mab said she would target him after Harry. That makes me think that he could take up any mantle associated with either winter or summer (Kringle for instance) regardless of whether becoming a Fae is an effect or not. I have no idea how the transformation to Fae would affect his demon. Would it disappear, remain unchanged, or morph into something else as well? Only Mr. Butcher would truly know.

I do like your theory that the supernatural community is somehow rooted in Outsiders. Maybe a segment of outsiders fled to our world in the very distant past to escape and set up the gate to keep the rest of the outsiders out. Over time they morphed into the beings we know now.