Source: The Wrestling Observer Newsletter
As noted late last night here on the website, CM Punk is still being advertised for the Elimination Chamber PPV and a few other future WWE shows but is currently being pulled from any and all future advertising due to his departure.
CM Punk met with Vince McMahon on Monday night to inform him that he would be leaving RAW and going home to Chicago. McMahon was busy with RAW re-writes all day, and did not meet with Punk until approximately 7:30PM ET, just 30-minutes prior to the start of RAW. That is the reason that the Alberto Del Rio vs. Kofi Kingston match went as long as it did as WWE had to fill the time that the CM Punk segment was to be in.
The WWE creative team had been operating under the assumption that Punk would not be staying with WWE after his contract expired in July. Several people backstage with knowledge of Punk's situation described him as "good as gone" from WWE come July.