I take it you are looking for reasons to switch or not to switch?
I say switch.
8 is superior to 7.2 in ALL respects in my opinion. It is more intuitive, has much better UI, is more fun and sounds better. I cannot think of one thing I miss from 7.3 which was my previous system. The price is better and the upgrading price is a joke. Seriously just take the plunge you will not regret it. All the good things are still there, most of the bad things have been removed or made better. Just getting rid of the XS key is almost worth the money alone. Add to that the fact that you get Mainstage, Soundtrack Pro and Compressor thrown in for free, oh yeah and all the garageband jampacks... it is a steal.... really .....