Certainly the case for me. I've a i7 920 D0 (IIRC) and have no compelling reason to upgrade it. It's never been overclocked either, which is another option if it comes to it.
I think it's a general thing across PC's at the moment. We've had a few good years of tech and not a huge amount is pushing it. I'm still using a 260GTX in my main system because there isn't really anything I do that it falls down on.
I just completed Portal 2 with it and it was absolutely fine (and I'm a frames per second whore).
If anything I'm more interested in the low power offerings that are coming about. The AMD chips and mobos you can pick up for media centre based stuff is fantastic.