Don't worry about a thing. I skied in the East and the West (and Europe) and you'll find the skiing in the West is far superior. I brought my skis east one season and never dragged them out there again.
Your biggest danger is that once you've "tasted" western skiing you'll never ski in the East again. If you fall, it's a soft fall. You may freak out, however, since it's so much fun!
That said, you should be prepared for lots of powder -- I'm in Aspen and we had three feet of snow over the last few days -- VERY unusual.
Powder is basically skiing in three dimensions, not just two. It takes a bit of extra balance -- don't lean back. The newer shaped skis are very helpful in all conditions including powder and make everything easy to ski. Edges are not that important and just take it easy (it's not eastern hard pack). Also, while you're used to cold, we are expecting some cold here so bring warm clothes -- you can always shed them. Finally, remember to zip up all your pockets or you'll find them full of snow!
As for moguls, when there is enough snow you won't find any. As for the steeps, you'll need them in order to move if the snow is deep enough.
If you're looking for some choices in terms of where you'll find the best snow, check www.onthesnow.com, www.skicentral.com or www.ski.com for snow conditions and other information about the resorts.
Have a great time!