As a pilot episode, this definitely has potential. I don't really know why I wanted to start watching this show...maybe the time-travel aspect intrigued me. I've read on the forums here that this idea has been done to death, but I've never watched any TV shows with it, so I'm good. I really enjoyed the acting and the time travel aspect to this show. It was nice, and the sense of urgency and excitement that you felt while watching Vassar discover his abilities was truly incredible. The writers smartly left a few questions unanswered in this pilot episode, namely his old crush Livia's role in the whole ordeal (Moon Bloodgood is the coolest name ever by the way).
I suppose if I had to pick a problem with the pilot episode of Journeyman, it would be that it seemed to move incredibly too fast. Vassar seemed all too eager to accept and understand the fact that he could randomly move through time without any real questioning. I thought that kind of unrealistic, but it didn't detract from the show too much.
All in all, a good debut. It's got me intrigued enough to watch the second episode.