Go for Galaxy s2 it much better,but wait for a samsung official statement for official jellybean update, if not always one can use cyanogenmod custom roms
First make clear about your needs or likes
If you want latest software updates,nothing beat a Nexus device on Android platform. As far as i know sony update policy is ok,but make sure you get ics and even jelly bean
Jelly bean is pipeline, None of the devices got it a part from nexus devices,wait for sony's official statement to see whether xperia p will be upgraded to JB aka 4.1 or not.
I request you wait and buy a phone which is Jelly bean upgradable
I hope you know about Jelly bean update,it has Butter like smoothness comparable to ios ,
or wait for a galaxy nexus,its price is dropped but yet to be available in india