Air Atlanta Europe/Air Atlanta Icelandic are indeed a wet lease operation. They operate for many other carriers, including two 747 classics in Virgin livery (which operate the daily MAN-Orlando service, for instance).
Recently they have started doing summer IT charters in their own name. Aircraft comprise the 747 classics (some ex-BA) and recently 767s etc.
Their primary business is also as a 'standby' for carriers such as Britannia. Spare aircraft kept on standby should a 767/A330 etc. go tech.
They certainly are not a one-plane outfit!
www.airatlanta.com for some background. jobs section .