The current plan is to close SummerSlam with the WWE Title Match, featuring CM Punk defending against John Cena and Big Show. This goes with the ongoing storyline about CM Punk and his WWE title defenses not being featured in the main events. Jim Ross also recently blogged and guessed that the title match would main event the show.
There has been talk of putting the WWE title on Cena in order to build to Rock vs. Cena II at the Royal Rumble, with talk of that leading to The Rock winning the title there and facing CM Punk at WrestleMania. Those plans are not confirmed at this time.
* The current plan for the Lesnar vs. Triple Hmatch looks to be to have Lesnar win in a dominant fashion. The feeling is that after losing his return match to John Cena, he needs the win more than Triple H does at this point.
As always, plans can and likely will change over the weekend. Stay tuned.