Alliterative verse would never have become as widely known as it is today if it were not for the work of scholars --medievalists, philologiss, and linguistics -- who painstakingly recovered, transcribed, analyzed, and translated the srviving corpus of medieval alliterative poems. J.R.R. Tolkien was one of the greatest of them, and (almost by accident) his hobby of inventing languages and stories to go with them turned into The Lord of the Rings. His work has done much to popularize alliterative verse, though it is important to realize that J.R.R. Tolkien, C.S. Lewis, and others of his generation were the inheritors of an earlier generation of 19th-Century scholars who discovered alliterative poetry and made the first steps toward popularizing it.
Of course, scholars of the Middle Ages -- philogogers, linguists, and others of that ilk -- are the obvious suspects where writing original alliterative poetry is concerned. And yes, many of them have indulged in precisely that guilty pleasure.
Note: The poetry linked here ranges in quality from novice work to brilliant. It is probably just the tenth of the iceberg that shows above the ocean. There is almost certainly much more out there. Send me links if you find them ... use the following email, making the standard substiution: pdeane[at]alliteration.net