Honestly, we're surprised it took this long.
The establishment in question is London's Georgian House Hotel, which has fashioned a number of its rooms after the living quarters at Hogwarts:
Rooms start at £249 a night and are furnished with potion bottles, spellbooks, trunks, etc. For £363 a night you get a package that includes a walking tour of some of the films' London landmarks and tickets to a "Making of Harry Potter" tour and Warner Bros. Studios.
If you're in the U.S., or if haunted mansions are more your style, we recommend the Haunted Winchester Mystery House (which also allows booze).
H/t The Independent