As a theatrical troupe, the Muppets haven't exactly been AWOL these past dozen years; the gang rocked YouTube in 2009 with their kick-ass rendition of Queen's 'Bohemian Rhapsody.' But they've certainly been lying low while our twitchy, tweet-y times have favored snarkier, more air-quote-driven entertainment, even from puppets. And in a way, that showbiz hiatus has worked in favor of The Muppets. For adults, the movie's gentle, clever, unironic humor feels freshly, trendily retro now, enhanced by laughs provided in cameos from a very up-to-date roster of stars.