WATCH THIS: Leno is funny! Really!

Could the old Jay be coming back? The Jay Leno who was such a sharp and loose dude while subbing for Johnny Carson, before he officially took over The Tonight Show and turned into such a safe-playing schmo?

There's intriguing evidence to the affirmative in a wild Leno location sketch NBC is using to promote Jay's new fall 10 p.m. weeknight hour -- a mockumentary with Jay driving one of his antique cars, hitting something bloody, shoving a cop into his trunk, and otherwise getting down and dirty. I haven't even chuckled at Leno in forever (maybe 1992), yet laughed out loud at this wicked viral-style promo being shown in movie theaters:

Leno actually used to have a dangerous edge, and a killer wit, back when he wasn't into public humiliation ("Jay-walking") and cue-card reading (the rest of the show). His nimble pre-Tonight standup always took the high road, directing barbs up at the powerful rather than down at common folk, and his late-night interviewing back then was relaxed, reactive and irreverent yet inclusive. When the sainted Carson was actually seeming stagnant behind the desk, reflecting a dated '50s booze-and-broads attitude, Leno bantered on contemporary terms with women, blacks and rebel celebs, rarely sucking-up and typically eliciting something fresh and real.

Fresh? Real? When's the last time almost anybody said that about Jay Leno? But his new mock-viral promo has that early-Jay sense of energy and honesty, even though it's nakedly concocted.

Could the Jay of 20 years ago, the guy who arguably merited his Tonight Show elevation, be making a comeback? I'm too cynical to get my hopes up much. Sure was fun, though, seeing The Good Jay make this reappearance.

(Thanks to Jamie Hibberd's fine TV blog The Live Feed for giving us the heads-up.)