If the gate agent doesn't mention elites in the First Class boarding call (and I haven't been upgraded) I will generally board with First. I kind of hold back until it looks like most of First has gone down the jetway and before they start general boarding. I've never been turned back.
Now, on my wish list would be for Mesaba and Pinnacle planes without a First Class Section to offer a pre board for elites. Perhaps Pinnacle does this, I know Mesaba doesn't. Since the only reason I really care to board early on these planes is to get bin space, it would be good. Continental Express does this and it is a nice benefit.