It looks like it will be puppet based. It's the standard Super Grover, but with major redesigns in the costume... a shinier new helmet with sharp looking ridges, a more pointy logo (edgy in superhero design means pointy, I guess)....a larger cape and large arm bands.
There are also 2 other segments that were just announced over at Tough Pigs... Goodnight, Elmo where Elmo and Louie go through their nightly getting ready for bed routine (say, isn't that what Pajamanimals was?) and (you'll like this one) Count TV where he hosts various number segments. Those two haven't been confirmed as season 41 regulars, though. They could very well be parts of the show, or just international short programs.
The info for all of these new segments is very thin, though.