Battery life isnt great on any of the current smartphones. If i use my Nexus-S for just calls and texts (in other words like a 90s phone!) then i have had 52 hours use from it….but if i have Wi-Fi switched on, browse the internet during the day, post on some forums, listen to music etc then it needs charging over night…no great hassle but compared to my old basic Nokia its pretty poor….my Nokia 2730 Classic would give 5 days use between charges!
I have a Nexus-S but in all honesty all the top smartphones do the same thing now.
They all have a decent camera, all browse the web at speeds you’d have been pleased with from a laptop a few years ago, all have integrated diaries/organisers, all have loads of Apps, great displays etc etc….
….basically pick the one you like the look of the most or can get the best deal on.
The only thing i will say is that the new dual core phones havent been the great leap forward that many had hoped, processor speed only went from 1Ghz on the top phones to 1.2Ghz and developers writing Apps havent done anything amazing with dual core facilities yet….the next round of dual core smartphones should be the next big step, everything that came out late last year (iPhone 4S, Galaxy Nexus, HTC Sensation etc) were good phones but not noticeably better than their predecessors.