There certainly are a lot of RACE07 servers online nowadays. The driver counts online have doubled since I got it, which is to be expected.
I used to run GTR2 online a bunch and that's quite busy, and figured it might just show how busy RACE07 could be once enough people finally found where to buy the sucker. And was particularly interested in running the P&G mod in GTR2. And never saw more than 3 or 4 servers running GTR2. So I'm quite happy with the numbers in the RACE07 lobby.
I always do a No-Password filter in Multiplayer so probably don't see all the active races, but it does seem RACE07 is building numbers.
Now what we need are some more HotLaps filed here @ NG so you can get an idea of what laptimes are going to work online.