NBA 2K10 or NBA 2k11?

It's really late now and with the announcing of NBA 2K12, I just don't know which one to get. I can't decide because I just want one of these two until 2K12 comes out, but I'm not willing to drop 30 dollars for 2k11 which will be outdated soon or should I buy 2k10 but that will become even older ( but it is cheaper) can someone help?