Team Meat is trying to rattle PETA's cage, mocking the animal rights organization for its inability to actually do anything substantial.
Never let it be said that Team Meat can't take a joke, even when that joke is a not-really-a-joke-at-all piece of pro-vegan programming. Team meat has embraced Tofu Boy, the lead character of PETA's Super Meat Boy parody, and is putting him in the main game itself.
Team Meat announced via Twitter that it had just finished animating Tofu Boy and would be adding him to the PC version of Super Meat Boy shortly. Team Meat apologized to Xbox 360 players, but said that it couldn't update the Live Arcade version in the same way. It also got in a parting shot at PETA, with the joke "How many PETA members does it take to change a lightbulb? ... None, PETA can't change anything."
Later, Team Meat's Edmund McMillan wrote a blog post about PETA's parody and Team Meat's subsequent mocking of the organization, saying that he had nothing against vegetarians or vegans, but that he couldn't support an organization that thought that nothing should ever be tested on an animal ever. He said that without the animal testing involved in developing insulin for diabetics, his best friend in the world would be dead.
PETA has yet to respond to the latest addition to Super Meat Boy and to the jokes about its lack of influence. As Team Meat is really just goading PETA into keeping the conflict going, the smartest thing for the organization to do would be to keep its collective mouth shut, but whether that's actually going to happen remains to be seen.