I have an nVidia GTX 280... It can handle anything to date and I'm getting this message, too.
I mean, I don't mind being told that my drivers are out of date, but don't plaster it all over the place like I'm an idiot. At least take the Steam approach and say "hey, there are updated drivers that you might want to check out, if not, fine, and you won't see this message EVER AGAIN."
Plus, Steam doesn't force me to reset my graphics settings to low or default settings in order to even start the game. I absolutely loathe this sort of approach. "Because our software THINKS your computer is using old technology, we're going to force you to change your graphics settings, okay?"
Again, it's nice to be alerted to driver updates, but I know my computer's capabilities better than any software does, and even if my computer might have low specs (which, I might add, it definitely does NOT), I should still be able to do what I want as far as graphics settings. If I want to chug along at 10FPS because I think it's a good trade-off for pretty pictures, let me do it. Ugh...
A minor cosmetic annoyance, to be sure, but it's still uncalled for.
I too get this message on startup. I have a Dell Latitude D830 with a Quadro NVS 140 chip with the latest Dell approved driver. Definitely below spec but it's been running the game so far at minimum settings. Whatever this patch was, it improved my performance considerably in space and on the ground.
I'm also getting this message; DELL Vostro 1500 w/ Nvidia GeForce 8400M GS; purchased about 2-3 years ago, and just updated with v195.62 drivers (latest from Nvidia web site) as of today. Probably a bug, and with the number of posts in this thread alone, I'm sure this will be taken care of fairly soon. It's a good idea to post your system specs if you're getting this message so the DEVs have some useful information to work from.