I too love this show and Jay Mohr's character but I think that his days are numbered. He is headlining a new comedy in the fall and while it's possible that he would be involved in both, it would be difficult.
He had one scene in last night's show and there were two (IMHO) "foreshadowing" events in the scene. His character is always messing around with books and re-arranging things in his office but rarely do they focus in on what he is picking up and moving unless it is significant - last night, when he picked up a pile of books, there was a very quick close up of the books - the book on top was "Ghosts Among us." Second event - when the phone rang, his character said, "if that's for me, I'm already gone" and he walks out of the scene. We don't see his character again until the end.
My last clue that it is him is that, while his character is full of information, he has no "gifts" to speak of. In order for him to see six people and only 5 shadows, he'd have to be "past tense" - otherwise, he'd see six people and six shadows or five people and five shadows.
I haven't felt this way at the end of the season since Melinda's best friend died during the plane crash and no one knew until Melinda hugged her brother at the end of the hour - kind of creepy, sad, and perplexed.
Like I said - just my theories. I'll definitely be back to watch in the fall!!