I decided to go with the SE Xperia X10 and I gotta say what an amazing 'phone'.
The interenet is as fast as you will get for a long time, 8.1 mega pixel camera with HD Recording (next update).
I downloaded an update for google maps this morning, the update was 3.4 meg, it downloaded the update in abour 5 seconds and installed it in about 5 seconds too. 10 seconds for the whole thing, even my PC would struggle with that!
The touchscreen is a little sluggish compared to the IPhone (I got an IPod Touch so it's easy to compare).
The Android market feels as good as Apples andf I think will surpass that eventually.
At the moment, i think the Xperia X10 is the most powerful phone around.
I had a Nokia N97 for a few days and thought it was useless, way to slow (the specs will help me on that one).