Are all the good game ideas taken?

There's going to be a new Devil May Cry coming soon. A reboot, from the looks of it.  Halo Reach just came out, the 3rd-and-a-half-kinda in the series. A new Metroid just hit recently, continuing a series that started on the NES. I don't even think I can count how many Mario games there have been and a new Donkey Kong is on its way. We aren't even going to Final Fantasy. There are a lot of sequels in gaming.
We all love the classic franchises. I love a good sequel as much as anybody, which all the hours I have into Mass Effect 2 will testify to. But at some point we have to wonder, where are the new ideas?
There are some good new games out there to be sure. Little Big Planet is delightful, clever and inventive. Dragon Age Origins has some great storytelling. So naturally there are already two big expansions and a sequel on the way. Uncharted is good stuff, fun and engaging. And of course it too has a sequel. Alan Wake is my kind of game, deep and thoughtful. But if you look at the game charts for the last year or so almost everything is a sequel of some sort. (Yes Red Dead Redemption is a sequel).
So what's going on? I want to talk to the more seasoned gamer, the ones who remember these franchises when they were 8 bit sprites struggling with bad animation. Is there too much sequelizing (is that a word?) in gaming? Is Bungie doing the right thing walking away from Halo while it's hot? Or are we ok with going along this same path, making every game like Tomb Raider, sequel after sequel, risking the watering down of what makes a game great?  Let me know what you think in the comments.