hey if can aford it. But here is a thought. buy the card anyhow and use your 460 as a back up. If you can wait all of these cards will soon be droping I don't know when but after the new cards have been out for a while and there price drops then the older cards will drop also.
Just food for thought. The 470 is a better card. But I wonder if you could SLI them that would give you two 460s. But I am not sure if you can or not. It might be worth checking out.