I upgraded from a Storm (right, no "2"), and even I feel the missing BBM, all-inclusive push email. I did find that maildroid does a good job of getting non-gmail accounts pushed to me, although the UI doesn't hold a candle yet to the BB email UI. Still, crazy-better than the stock Android email app, so go for it IMO.
Otherwise, there isn't a whole lot to miss. I personally love the learning curve, as it ultimately = customization (and I'm used to learning new computing environments). I've already set up 5 of my 7 pages, including a nice Sense-ish home page, and know what is going on the other two.
I think I finally solved the battery issues I had tonight. I still wish widgets were fed via push-data rather than server checks, but that's not a combination that's available to us atm. Enjoy your new phone!