Added spoiler space for anyone who hasn't seen it yet!
I'm still sort of mulling this one over. The way they were promoting it, we were going to finally see "the return of Mulder" which it didn't end up really being. I think it cleared the way for when Mulder does come back to be miraculously "cured" of the brain disease Scully and Skinner found in his file, but other than that, it didn't really advance the whole storyline much. The Doggett thing was dumb, IMO - X-Files works best when at least one of the agents is the skeptic - how can you maintain objectivity when you've been killed, eaten by some mutant then barfed back up and brought back to life?
On the other hand, it was nice to see Doggett step into the main role, and I think R. Patrick did a good enough job that he proved he can carry his share of the series if Gillian decides to go another year without Duchovny.
It was nice to see Skinner again.