In summary: The game was first announced all the way back in 1999, with a trailer at E3 the same year. It then hopped from console to console, and even through three different generations, starting with the original PlayStation (with a Sega Saturn port), going to the GameCubenote due to their exclusive partnership with Nintendo at the time, to finally settle on the Xbox 360note which was decided upon because Silicon Knights burned bridges with Nintendo when CEO Denis Dyack, who wanted the prettiest graphics, discovered first-hand just how powerful the Wii was.. The only game to be in development hell longer and be released would be Duke Nukem Forever, and, as most people will tell you, that's not even a safe bet either.
Not so much, given that both new and used copies are still extremely cheap and easy to find online. Plus Silicon Knights did not have the power to recall unsold copies of the game, so those may still be out there as well.