Robert DeNiro and Jimmy Fallon, Late Night with Jimmy Fallon

Yeah, it used to bug me too how he cracked up all the time during SNL skits, but there's no denying that Jimmy Fallon is a funny guy. But is he late-night-talk-show funny? Let's investigate!

CONAN! In the show's first segment, Jimmy is sitting in his dressing room, and the camera goes wide to reveal his Late Night predecessor Conan O'Brien, packing boxes. "I was going to, like, TiVo it or something," Conan says mock-dismissively of Jimmy's first show. When Jimmy tries to comfort Conan by suggesting that he'll now get Jay's old dressing room, Conan says flatly: "Jay isn't leaving."

MONOLOGUE! Jimmy seems nervous. Some jokes are hits; some are misses, but none knock my socks off, until... Jimmy and Tariq from house band The Roots collaborate on "slow-jamming the news." As Jimmy recites a topical musing about Speaker of the House Nancy Pelosi and the economic-stimulus package, Tariq backs him up with smoove grooves like "You can't rush my stimulus, baby" and "Now bring me that little piece of legislation and put it on my docket, baby." I could see it becoming a welcome recurring element to the show's opening.

BLOND MOTHERS! There's a brief skit about an attractive demographic that Jimmy's advertisers would like him to court: blond mothers from Connecticut. There's a pastel-painted row of them in the audience, and a video package reveals that they are "less sick and sad than their brunette counterparts," and that they have "discreet dolphin tattoos that say 'I'm two Chardonnays away from ruining your wedding reception.'" Is that you, Auntie Betsy?

LICK IT FOR TEN! This is exactly what it sounds like, and owes a debt to surreal Letterman bits like "Is This Anything?" Audience members lick a lawnmower, a computer printer and a goldfish bowl for $10, and if it weren't for the segment's "super-sexy replay," I'd call it unredeemably unfunny.

ROBERT DE NIRO! De Niro is, of course, Hollywood royalty, but he's not what you'd call a dynamic, lively choice for a talk show's first guest. De Niro's "fake" grumpy-grampy routine hits a little too close to the truth, as he spends most of his time on the couch looking like he'd rather be playing Russian Roulette with the Viet Cong. There is no danger of De Niro being that oddball favorite recurring guest with whom Jimmy has rock-solid chemistry any time soon.

Jimmy offers that they have had similar film careers, as De Niro was in Taxi Driver and Fallon was in Taxi. So... they do impressions of each other. Jimmy's is serviceable facially, though the voice is way off. Then De Niro does a horribly silly-voiced riff on Fallon — "Hi, I'm Jimmy Fallon, and I'm in a moo-vee," he squeaks — and it comes off as kind of mean, though I admit I laughed a little, mostly because it was coming out of De Niro's mouth. Next is an awful skit about the never-released movie they claim to have done together: Space Train. It's as bad as it sounds. De Niro gets props for agreeing to appear in a skit for Jimmy's first night, but overall I was hoping he'd be more game.

JUSTIN TIMBERLAKE! Before Jimmy has to ask De Niro about his motivation for Rocky and Bullwinkle, JT shows up to rescue his buddy. As we've seen from Timberlake's many appearances on SNL, the man is a pro. In addition to reprising their "Barry Gibb Talk Show" shtick, Timberlake does pitch-perfect impressions of John Mayer — it's like "Macy Gray and Smokey Robinson, no, Smokey the Bear, had a love child," he says — and Michael McDonald recording a jingle for Bud Light Lime (ew), one of Jimmy's sponsors.

Timberlake is also there to plug a new MTV show he's executive-producing: The Phone. It sounds kind of like that movie Phone Booth crossed with Punk'd, in which, under the guise of winning a cash prize, Timberlake & Co. basically "scare the living bejesus out of people" for 24 hours straight. It doesn't look bad actually. It's "like The Amazing Race, only better," Timberlake boasts.

During this segment, De Niro mopes on the couch looking like he's at jury duty or something.

VAN MORRISON! Van Morrison shows up to close the show with a cut from his new live album, and Jimmy runs into the audience and kisses his parents. Aw.

AND... SCENE! All in all, I think Jimmy will be just fine. True, he's no Conan (yet), but he's cooler than Leno and appears to understand the format better than Carson Daly. Only time will tell.

What did you think of Jimmy's first night? Are you excited to see how his hosting chops will fare with the three graces of Tina Fey, Drew Barrymore and Cameron Diaz, all of whom will stop by this week? Make some snap judgments with me!