Unfortunately, no Super Meat Boy: Forever isn't a mashup of Super Meat Boy and Katamari Damacy. But the good news is, it doesn't involve Duke Nukem either.
Last night, Edmund McMillen announced on Team Meat's blog that the game they had registered to show off at PAX "A Voyeur for September" is actually a new Super Meat Boy game they've been working on for the past couple of months-hooray for anagrams! Super Meat Boy: Forever is a new full-length platformer that is being designed with touch devices in mind, but won't be exclusive to phones and tablets. The only other platform that McMillen has announced is Steam, but there might more more later.
McMillen states in his FAQ sheet that SMB:F is not a remake or port of the original Super Meat Boy, it's a new game with it's own six chapter story, a dark world that has it's own dark warp zones, new playable indie game characters, and a randomly generated level structure that will change each time you die. Judging by the screenshots and GIFs included in the announcement, it will have a lot of Runner elements, and there will be an endless mode- but the game is not an endless runner, nor does it have one-button controls.
Team Meat is currently at the Indie Megabooth at PAX, so if you or someone you know is there, be sure to see what they've come up with so far for Super Meat Boy: Forever.