just cruised the wonder earlier this month and loved it! unfortunately for you, it was the first time i had been on it so i don't know what would be new vs. old..
i can tell you what we really enjoyed:
1. Disney Dreams - an incredible production
2. Hercules the Muse-ical - a great production as well
3. Who wants to be a mousketeer - cool prizes if you get called up to the hot seat...
4. First run movies (they were showing Sweet Home Alabama on my cruise) as well as old classics...
5. Pools, food, drinks, stores, all great
6. We even got sucked into playing Bingo and had a great time (we split the jackpot of $700 on the last night and that helped)...
7. the espn skybox (or whatever the official name is) had a really great setup (stadium like) to watch the game in
8. castaway cay is a phenomenal place, all on it's own... loved it there!!!!
we loved the entire thing, but those were some of our key points.... have a great time!