I thought the Quake 2 single player was pretty damn fun. If they redid it with the Doom 3 engine, I'd be first in line to buy it.
I probably agree with the stigma that Id now only makes engines, and can't make a fun game with it anymore (although I guess the umpteen million people who played Quake 3 probably wouldn't agree), but that doesn't mean that their engines aren't the absolute finest in the industry (and I'm sure I'll get a lot of Unreal fan flames for this).
I think Id just lost too much creative talent to really come up with something spectacular anymore. I'm fine with them just making the engine, farming it out, and letting others make great games with it though.
In fact, I would prefer it if game development would get centered around two or three engines at most. While it's fun to see a new developer build their own new kick-ass engine, it definitely adds to the "this driver works with that engine, but at that setting, while so and so third party driver does best with this engine, and that engine just doesn't work because of my soundcard, and this..." etc etc
With fewer engines, I would think actually getting games to work like they should would become easier on the PC, as opposed to the fucking hassles most of the PC gameplaying crowd has been put through the last few years.
Still really hoping Doom 3 will come out April 15th..