Cary Grant was soft. You can see it in the way he'd lower his shoulders to embrace someone. I don't mean "soft" as a euphemism for "gay"--although how Grant swung might have influenced his softness. What matters is that he had it, and it balanced his wit, which was penetrating, so that he appeared generous and impatient: easy body and pushy eyes (i.e., the perfect suitor).
I say all this about Cary Grant because Peyton Reed's Down With Love is an unfunny knockoff of the Rock Hudson/Doris Day romantic comedies, which were unfunny knockoffs of Grant's romantic comedies. And because the reflexively campy Down With Love, for all its fantastical swingin' '60s fashion and gadgetry, makes sexual attraction look about as appealing as a broken lava lamp at a former hipster's garage sale. I say what I say about Cary Grant because romantic comedies are dire these days (just try to name five good ones from the last 20 years; you're disqualified if any of them involve Meg Ryan), and because the one movie star who could approach Cary Grant in that killing softness is fluent in love only in Cantonese, and has made a career of playing with guns, not dolls.
Ewan McGregor does heroin addiction extremely well and mystical light-saber guru-ing better with each attempt, but as Down With Love's Obi Don Juan he's a Jack Russell terrier with a stray sock. Granted, he's been given little but the smart sets to chew on. What suspense there is arises from the writers' dilemma: Given their established battle between a callous playboy and a (thinly disguised) maid with marriage on her mind, how can the sexual stereotypes be both evaded and placated so that the target audience of youngish career women can feel at once smug and titillated? The answer is a cliché that might've had teeth if there were any bing-batta-boom between McGregor and Renée Zellweger (the maid). There ain't.
I'd say it's Zellweger's fault--or at least the fault of her lips, which purse too often in a way that will haunt me in the afterlife. Zellweger plays a country gal, Barbara Novak, who writes a sexy bestseller advocating that women give up love but not men in order to achieve career equality. Decked in designer duds, Novak is seemingly the anti-Bridget Jones, but the same love-hunger lurks underneath. Zellweger smiles so tightly that her upper lip disappears: She's thin, in every sense, as is this movie. Oh, for softer shoulders and more liberal wit.