Well, according to F4WOnline via WrestlingInc.com, WrestleMania XXX may be his opportunity. Early reports state that CM Punk is slated to win next year's Royal Rumble match and accomplish his dream by main-eventing at WrestleMania. Not only is it aWrestleMania, but it is the WrestleMania—the most monumental one ever.
http://bleacherreport.com/articles/1687633-wwe-news-early-report-on-potential-royal-rumble-winner
WWE Champion Daniel Bryan VS CM Punk in a 60 minutes Ironman match at WXXX. Book it!