According to the spec, draft 2.0 n products do not need to be retested, so you can go and scratch the draft word on the logo you find on any of your draft 2.0 n product away and then shout out you have a final n product. That's it.
I was kinda on edge about this final stuff, as I've just bought the DIR-655 recently but after reading the spec carefully, that was what it said.
As for firmware I hope dlink do it better next time on the stability, reliability and compatibility (maybe, some have it, I don't have compatibility problem) fronts.