In todays age, consoles offer one thing: Consistency. You don't need to see if you have enough RAM or HD space, or if your video card is up to date, you just look and see 'Ah, this is an X-Box' and know that the game should play exactly as well on your machine as it does on any other.
When consoles come out, there's a brief window where they might have better graphics then a PC game, but that quickly expires. The X-Box comparison, for example, is easy to see. It's a 700mhz Celeron processor with a video card that might run Aces High II, or might not. It's borderline.