The game looks fun indeed but I never got that feeling of having to go out of my way to buy it like I get with other games.
The craze could be explained by Nintendo fans having another release from their favorite company and enjoying it. Plus it is all colorful and stuff, the way they like them games.
I don't have proof for any of the following, but I have this hunch that maybe there are a lot of Nintendo fans that may suffer hemophobia or something. That would explain the way that some of them have this immediate reaction of repelling anything with gore and Kool-aid spilling action that comes their way. This may be good material for an specific study in the future, interesting stuff.
Mod edit, all cleared up - Leadified
Nintendo is selling their IPs to Microsoft and this is true because:
http://gamrconnect.vgchartz.com/thread.php?id=221391&page=1
