First, you need to think about iTunes in general...
iTunes 11 has changed A LOT of things. Heck, they built it from the ground up pretty much. Everything from the What's Playing little box at the top, to how things work.
Next, you need to know how skinning works...
When people skin things, whether it be iOS, OS X, or apps, they are limited to what's there. In this case, we are only limited to the resources in the last supported iTunes on PowerPCs.
Pretty much what I'm saying is that even if someone does go in and try and theme iTunes 10 to match 11, there are going to be many, many, many differences.
And skinning doesn't take overnight tweaking, it takes a good while to do it right.
So calm down, sit back, and relax. I'm sure someone is thinking about doing it, but it is waaaayyy too soon.