That's one of the uses of a Randall (the name given a type of filter through which beer is passed between keg and tap; when filled with fresh hop cones and used with a high-alcohol beer the alcohol pulls the hop oils from the hops and infuses a very assertive fresh-hop flavor to a beer) but I've also attended a northern California beer festival where a Berliner weisse was served through a Randall filled with raspberries. A very refreshing drink and an interesting take on the typical squirt of fruit syrup added to beers of that style.

But the large majority of places serving Dogfish Head's and other breweries' hoppy beers don't even own a Randall, much less serve a particular beer through it all the time. The effort and expense of getting a twice-or-thrice-daily load of fresh hops for Randallization makes that improbable. I don't know of any bar or brewpub that uses a Randall more often than weekly, and even then it's only for a couple of hours.