Sounds like a nice little idea that serves as a midpoint between the non-functional aesthetic purchase feature and the balance-shattering gameplay purchase feature. From the sound of the names, they probably don't serve any direct purpose in-game, but they do serve to just be fun little trinkets (Riding around on a creeper? Sounds neat.)
Of course, there's also the chance this is just a joke, especially given how ludicrous some of the prices are and how silly some of the items seem. 99 dollars for a name change is the biggest indicator, considering 15 dollars could just buy you a new copy of the game under a different name.
Edit: After looking around a bit more, I'm fairly certain this is just a joke. Notice the 5-pack of keys costs as much as 6 keys would. The "response from support" is a crack at the number of people who complain because when they submit a bug report, Mojang rarely ever sends a response (they usually get to work on it instead of wasting time writing a response to the several million reports they receive every week)
Second edit: Oh yeah, Notch is in a different time zone, so it's already April Fool's day for him. That explains it.
Of course, there's also the chance this is just a joke, especially given how ludicrous some of the prices are and how silly some of the items seem. 99 dollars for a name change is the biggest indicator, considering 15 dollars could just buy you a new copy of the game under a different name.
Edit: After looking around a bit more, I'm fairly certain this is just a joke. Notice the 5-pack of keys costs as much as 6 keys would. The "response from support" is a crack at the number of people who complain because when they submit a bug report, Mojang rarely ever sends a response (they usually get to work on it instead of wasting time writing a response to the several million reports they receive every week)
Second edit: Oh yeah, Notch is in a different time zone, so it's already April Fool's day for him. That explains it.