I fell on my 15" Unibody MBP on a slippery sidewalk in January (snow/ice), with my arm between the sidewalk and the laptop and the entire weight of my chest on the lid... it looks quite like yours now, though not as badly warped, with a bent ethernet port and a warped expresscard slot. Every body panel is warped, the trackpad is flush with the surface on the left bottom corner and the normal half millimeter recessed in the others; it only works (= physically clickable) when it's on a level surface. Screen edges bent downwards and scratching on the case. And I dropped it a second time since from 4ft onto a stone floor (and spilled wine over the keyboard 😛)
And everything still works 🙂 (well, the hard drive made funny clicks after the first incident, so I replaced it)
For the record, I checked with the Apple store here in Munich, and they gave me the prices for a new top case and a new lid (including LCD panel etc) and some other parts. Was less than 1000 euros. The lid including the display was surprisingly cheap, I think around 300.
The annoying thing of course is that I have AppleCare on this thing, which is useless unless I get the repair work done to restore it to a state where they won't say "well you dropped it you oaf, of course it's broken" should I ever bring it in in case of a defect.