I wouldn't say the DT770 aren't all that great, just that for a few dollars more, you can have better. I'd personally choose the D2000 first, if it's anything like the D7000. Considering the Creative Aurvana Live is pretty much a slightly improved D1001, and I find the CAL to be comparable to the DT770 Pro 80, it would make sense to hold out for some D2000s.
If it wasn't for the fact that I really don't want a pair of cans with leather/pleather pads, the D2000 would be in my house right now.
Interesting. I'm being lazy here and assuming that the D5k's and the D7k's aren't closed sets? With the D2k's, what, if anything would you use to power them? I'm looking to use a portable amp, not something I have to leave on a table.