Like some of the rest of you, pretty much every time I have a wet dream, I wake up as I'm cumming. The orgasms I have from a wet dream are fantastic, not like cumming from sex or masturbation. Maybe they're more intense since they usually occur due to not having cum for a while.
When I've had a wet dream cum, I feel totally different afterward too - there's none of the feeling I usually get after orgasm where I just don't feel like cumming ever again. With a wet dream orgasm, it's kind of the opposite - I usually stay hard for ages, and really feel like just grabbing my cock and wanking to another orgasm using all the semen!
Unfortunately, I've never really been in a position to keep going after a wet dream orgasm. Hopefully one day I'll be able to try it!