I would seriously rethink that Sony Xperia purchase. Last years' hardware, only guaranteed an update to 2.1 from 1.6, awesome camera though; however I'm on the fence with the rest. Especially the fact it has - I think - only 384mb of RAM and basically 1gb internal + microSD whereas the Samsung Galaxy S has 512mb RAM and 16gb internal + microSD.

And the newer phones around the corner improve on that - Sony phones inclusive.