As much as CS2 is a great new edition, let me tell you the downfalls.

Lags, because CS2 has so much.. it takes A LOT of memory and you will lag. (especially when you use the photobridge)
The layer options have changed.. it's more professional but it may be harder for newer users.
There is no "link" under layers anymore you must select your layers in the panel and use your shift key to pick which layer you want and then hit ctrl e or the link button on the bottom.

another addition I'm so well pleased that CS2 has... when you view your fonts it shows the actual font style so you can pick more easily.
I've had CS2 for a month and a half if you have any questions i may be able to help you.