I got to play with an X at a mall Verizon store today (King of Prussia, PA) (I tried at a different store yesterday and they handed me a dummy). A couple of impressions -
1. It doesn't seem all that big -- I'm small (5'0") with small hands and it felt fine, except maybe that....
2. Swyping with just my thumb, while holding the phone (duh), was just a bit of a stretch for me. I would have to get the hang of Swype, but it was great as a first impression.
3. Colors were bright and pretty - I have a Dinc and opened it up to compare. The incredible is definitely much crisper and brighter (darker black, redder red) but the X colors were fine.
4. I opened up a news article under Google news, and couldn't enlarge it with the pinch-zoom feature (not sure what it's called). On my Dinc I was able to. The Verizon guy said it was because I was on a mobile webpage (?). Not sure what to think of that.
5. When the web page first opened on both the Dinc and the X, I could read the teeny print on the Dinc, but it wasn't legible on the X. I doubt that would be an issue for me, since I'd enlarge it to read, in any case (though apparently can't with pinch-zoom??).
6. The keyboard was truly good -- easier to type on than the Dinc. Swype was tons of fun, too. It's pretty amazing.
7. The X did not have the "heft" of the Dinc. I have a Seidio Innocase II case on my incredible, but overall it felt heavier than the X. I kind of like the weight, but probably won't miss it.
8. The camera was pretty good - comparable to the Dinc, but I took only a few photos in the store.
9. Didn't make any calls. The Dinc dropped a call to my family from the mall, by the way
10. The "bump" was totally unimportant.
Those are my impressions - FWIW!