I asked a bartender what she was drinking near the end of her shift. She said a blend. Of Bear Republic's Racer 5 IPA and North Coast's Le Merle (a Belgian Saison).
I tried it and it was great. I already liked Le Merle except it had a bit too much of the Belgian kick, and I never liked Racer 5 at all, but together somehow the attributes I didn't like canceled out or masked one another.
At the risk of heresy, I wonder if mixing beers is or was ever a (semi-)official thing anywhere. I've heard wine blends mostly exist as a product of leftover grapes, so their justification doesn't apply to beer. Still, if the taste is great, why not have beer blends? With the distinct taste variations of hops alone, I wouldn't be surprised if great combinations could be found.
So, to put succinctly: Are beer blends being served anywhere?