I agree, ID's games today aren't as ground breaking as they were in the early 90s for obvious reasons. Success is a lot to live up to, and in my opinion Quake 4 looks like it offers nothing different than Quake 3 did, apart from the graphical progressions. Really, what have ID changed in Quake 4 when compared to Q3 gameplay wise? Enemy Terrority still looks interesting though.

Time will tell though, I think the game will still sell quite well. I also think the Doom 3 film will be a success in the box office, just like those lame Resident Evil films were.