I like what tom says.
The more honest you are up front the less likely you will have to deal with crap from friends down the road. MY closest friend here surprised me but not seeming to care that I "needed a break" when I told him. He has not seemed to give my not drinking a second thought. It has been a couple of weeks since I told him I was going on the wagon. Last night he asked me when I was going to start drinking again that he was bored drinking alone. I simply said that I didn't plan on starting again and that ended the conversation. Yes he has just as big a problem with alcohol as I do. I am not sure how our friendship will turn out as my being sober is more important to me than any relationship with him is.
I am starting to believe that if you play games you will have to deal with the subject longer than if you are as upfront as you can be in the beginning.
Good Luck