It's just a codename, and like all Microsoft codenames the past few years, it's taken from the Halo games. It doesn't really mean anything, and it probably won't be the final name, but who knows.
Cortana made it from code name to product name, as did Windows 7.
XBox too.
Because Halo is the strongest brand Microsoft has built in the last fifteen years.
Well now they own minecraft. So perhaps they can call this "Creeper"