I was trying to form one here in PA about this time last year. I came across a guitarist that is a fanatic too, and I was thinking about asking my current drummer (who loves Rush) to handle the skins. It didnt go anywhere mostly because of a singer. To me, thats the hardest part of trying to be a Rush tribute, the vocals. If you try to sound like Geddy, it just makes me wince.
I am in a classic rock cover band now and we do 2 Rush songs, and my guitarist handles the vocals. He isnt trying to sound just like Geddy but he does sing up high, and it actually works pretty well. I would love to start one up and if I leave this band at any point, I am going to try to really get one going.