Siliconera dug up the paperwork, which gives us very little information beyond a name and the potential for hours of speculation on what it means.
The most obvious guess would be it's the name of the new Hitman game, in production under IO supervision at the Square Enix studio in Montreal. Considering Hitman: Absolution won't be ready until sometime in 2012, it'd be surprising if Square had already filed trademarks on the next installment.
Hitman: Profession could also be some kind of transmedia tie-in, mimicing Ubisoft's Assassin's Creed model and creating experiences -- loosely tied to the core game -- covering comics, iOS and Facebook. Like we said: speculation!