Surprised no one mentioned this yet.
But since his last album he finally fulfilled his contractual obligation and now he's "more" free to do other stuff.
But Weird Al has always sprinkled himself here and there. Closer to 2010 he was a side character in MLP, Adventure Time and other shows and played himself in a bunch of live stuff like How I Fucked Your Dead Mon and 30 Rock.
And like other people said, his last album put him back in the spotlight.