FWIW, I heard that the emissions Nazis are slowly going the way of the buffalo. Ft Collins has done away with Envirosuck since Jan 1st. Diesel are still every year, however. It will be slow to hit the Denver area I'm told, but it is unclear what the process will be to register vehicle with regards to emissions.
Granted this is not first hand knowledge, but thru the grapevine. I hope that enviro-suck does go away.
I read that it is in fact going away, to be replaced with roadside tests. Not for a few years though.