For those of you who are near Chicago, iHobby Expo is returning on October 20th & 21st, 2007.
There should be quite a few manufacturers there, Woodland Scenics, Bachman, Athearn, MRC, Walthers, MTH, Lionel, Kalmbach, LGB of America, Marklin, and Kato to name a few.
Theres a quite a few operating railroads there as well, a map can be seen below.
http://www.ihobbyexpo.com/floor_maps.cfm
I took some footage of the show last year and posted it on youtube.
http://www.youtube.com/ihobbyexpotrain
It should be a good time.
-Kurt