There seems to be a bit of a anti-Halo theme here...
Anyway, for me Halo is not original at all. It's cliched throughout and the story is unoriginal at best. And that is why I love it. Now hear me out, Halo hasn't really done very much new at all but why would it need to? Halo has pulled various "good bit's" out of previous FPS's, crafted them into one game, and given it a story that, although it may not be the most original, is so well written that it works beautifully. The game is the pinnacle of simplicity: you play the good guys and you kill the bad guys; human guns and alien guns have different strengths and weaknesses, and you don't have to think whilst playing, it's simply just see baddy, shoot baddy.
I'm not sure where I stand on the Halo series inre raising the bar for all modern FPS's. It certainly, at least in my opinion, is a good game/series, it does what it does well and sticks to a winning formula but as for setting standards I'm not so sure. There are plenty of good FPS's out there (the Half-Life series for one) but they don't seem to try to imitate Halo, they have their own aspects that work for them, e.g. CoD games are applauded for realism, Halo isn't. Both are good but for different reasons. I would argue that instead of Halo setting standards it's more a case of developers using the technology available to them to make all, or at least most, modern FPS's to a higher standard. Maybe Halo gets at least some recognition due to the fact it was such a hit but it certainly wasn't the only good FPS out at the time and also it is definitely not the only good FPS since it's release.