CM Punk made his long-awaited debut in UFC 203 in Cleveland this evening, and got handily beaten by Mickey Gall. Within the first several seconds, Gall had Punk down on the ground and from that point it was a matter of when and not if he would win the fight.
Credit CM Punk for getting in the ring and taking that beating, but there was never any point where the match was in question. Punk tapped out to a rear-naked chokehold less than halfway through the first round.
It would be very surprising, at this juncture, if Punk appears in UFC again. [UPDATE: Punk implied in his post fight interview that he will be back.]
This is what Punk looked like after the match: