WaitWHAT said:
THANK YOU! Someone needed to say it without fear of being flamed by insecure P.C. nerds desperately trying to justify their $5000 rig. Graphics are not, and have never been, what gaming is all about. As it stands, we're seeing terrible problems with people trying to recoup costs on the games they've made even with current gen graphics. Maybe once we've got beyond the situation where stuff like this [http://www.escapistmagazine.com/news/view/117931-EA-Aims-to-Broaden-Dead-Space-Audience] happens, we can think about graphics. But not before then.
It's not just graphics, though. There's severe limitations on other hardware, such as RAM and CPU speed.
For instance, an Xbox 360 trying to play this,
http://2.bp.blogspot.com/-0yeT--9fCgY/TlpSXE-2qiI/AAAAAAAABng/XRj-rPNWhS8/s1600/Dwarf_Fortress_Ascii.png
...would still slow to a crawl during an invasion, water routing, volcanic eruption, large explosion, etc. because of the massive amount of calculations it uses.
Then again, it's John Carmack. He'd probably be able to optimize it, if we ignore the zeppelin-crash that was RAGE.