upgrading from your 460 to 660 will give you almost 90% boost performance in games..http://www.anandtech.com/bench/Product/542?vs=660
yes, you'll not regret it..
next generation card always faster than today card..
if you have to wait, why not wait until the launch of GTX99999999 ?
if this card in the future is too slow, grab another $500, and upgrade your card again..