I did pretty much all of my drinking alone, so no drinking buddies to speak of here, either.
But in talking to friends and acquaintances, I've gotten two distinct reactions. The person either (1) doesn't know how to react, skates over the issue and doesn't bring it up, or (2) is really, really supportive. I haven't gotten a single negative reaction to the fact that I'm in recovery.
I think, most often, people will take their cue from you. If you act ashamed they'll think it's shameful. If you treat it casually, they won't think much of it. If it's clear you're proud of yourself, they'll make sure you know how proud they are. That's my experience, anyway.