He should take some time off. It's known (or speculated) that Punk is not at full 100% health but is pulling through because it's Wrestlemania season. After his long reign and losing a bunch of times in a row, some time off after Wrestlemania to cool his jets would probably be best.
I made a thread a short while ago saying it'd be cool to see two of the big matches at Wrestlemania being combined into a tag match at Extreme Rules (Punk/Brock vs Triple H/Undertaker.) Seeing Brock and Punk actually work together at least once would be nice, as would Triple H and Undertaker working together given their history over the past couple of years. Imagine after Wrestlemania if Brock and HHH keep feuding and Punk joins in on destroying Triple H and ending his career forever. Maybe Stephanie even gets involved and Punk holds her down and makes her watch Brock pummel Triple H while he's handcuffed or something, and then Taker's gong hits and Punk and Brock leave the ring. Taker coming to both Triple H and Steph's rescue would be awesome. This leads to the tag team match at ER, which would make for a great double main event, with Cena/Rock III happening at the event as well.
This leads to Punk and Brock turning on one another, which writes itself, with the rumor of them feuding later in the year and all. They have issues, maybe Heyman pretends to side with Punk but then makes the turn and sides with Brock instead, who attacks Punk and puts him on the shelf for a few months.