Cool. The trailer saves me the trouble of synopsizing the plot. Watch it:
That's pretty much it. Gold-digger Cameron Diaz is a cruddy teacher looking for a man to take care of her and is only working to by the boob job she thinks is the key to achieving this goal. Hijinks ensue.
While it's clear the producers are trying to catch some of the aura of 2003's black comedy (as in dark humor, not Tyler Perry) Bad Santa in the title here, the key difference is that Billy Bob Thornton's thieving Santa was a moral degenerate and generally reprehensible lowlife and Diaz is just a goofy dame who is so close to being acceptable that she can clean her act up in an instant. Nothing wrong with that, but instead of calling it Bad Teacher, something like Classless Teacher would've sufficed.
Diaz is cute and funny as are Timberlake and Segel, but the consistent standout isn't Lucy Punch as many reviews have singled out, though she's fine, but Phyllis Smith (from The Office), as the timid portly teacher who befriends Diaz despite her shallowness. She puts a spin on her performance that makes it magnetic to watch, more so that the more familiar take Punch applies to her rabid Miss Squirrel.
The problem with Bad Teacher is that it's just not bad enough. But, it's OK.
Score: 5/10. Catch it on cable.