Not anymore: Tonya, Danny, and Leif are gone. Matter of fact, half of the old cast is gone at the point: we still have Brad Loekle, Bryan Callen (the only two from the VERY beginning), Billy Kimball, John Enos, Ted Jessup, Daisy Gardner, Mike Trainor, Mike Britt, and Jaime Andrews, but at the same time we've also lost Judy Gold, Loni Love, Chuck Nice, Frank Stallone, Chelsea Peretti, Daniel Baldwin, Nick DiPaolo, Roger Lodge, Chris Strait, Gary Busey, Michael Loftus, Wes Dening, Jessie Cantrell, among others.
We still have some of the more recent additions like Chris Fairbanks, Jamie Lee, Rachel Feinstein, and Brendan Walsh, but other than that, they have a completely new cast of commentators now of a bunch of E and F-listers nobody's ever heard of before... and Gilbert Gottfried. Not only that, but they've kind of changed the format of the show from being a strictly celebrity commentary show to being some kind of weird hybrid of a celebrity commentary show and a sketch comedy show.
They do have some better-looking graphics now (they're blue instead of yellow/orange), but other than that, the new WORLD'S DUMBEST... sucks.
From what I understand, though, Chelsea is on that new Andy Samberg show on FOX, Danny and Todd were recently on Oprah's OWN channel and seem to be doing really well these days, Leif was on HLN recently talking about Miley's twerking episode from a washed-up teen idol's perspective (and seemed completely stoned and out of it the entire interview), and I think Loni's coming out with a book. Not sure what the rest of the old cast is up to these days.