I am thinking of buying samsung galaxy S II.
I would like to know, does this phone capable to support ICS ?
Because I am not sure if to buy now and just upgrade the phone to then next OS or should I wait to but the next phone version?
SII will get the official ICS update in 1st quarter of 2012
Yes you can. Check out xda. They have got cm9.
I guess as of now,the ICS is available only to Nexus. Not sure whether you can update it on Samsung Galaxy.