At this point I'd wait for the 6D since we already know that it exists and when it will come. Reason why is, I'd be asking myself... Will I be happy with a 5D mark ii knowing there's a body out there that costs just a bit more but improves on major things like sensor noise, processing speed, metering, and center AF sensitivity? I'd probably die inside every time I saw a 6D owner watching them shoot photos with just a bit more ease and speed while I wait for my 5d mark ii to clear buffer. Then again, I already have fast bodies so it doesn't affect me too much to run it alongside. But if I had a t2i, I wouldn't pair a 5d mark ii with it. I'd probably replace my t2i with a used 7D first, and then save for a 6D. And then eventually replace the 7D with another full frame body like 5d mark iii or iv if and when it ever comes out. Going straight to a 6D wouldn't be too bad of an idea either. Just my personal opinion.