Half the people would play 1.1 for the mods (KorX, Zombie mod, Funserver mod, etc.), and the other half of the people would play 1.2 for the newness of it and the graphics.
I have tremfusion.....
I'm just saying that if your client were to be made compatible with the mods from 1.1, then people could move their modded servers from 1.1 to 1.2 version with no trouble at all, therefore leaving no excuses to stay with 1.1, therefore focusing every single tremulous server into one area.
(I still play 1.1 for the mods, and I know that a lot of people play gpp)