Marco Arment:

The much more likely explanation is that iPad2,5 and iPad2,6 are the new “iPad Mini” in Wi-Fi and GSM[…] If so, this suggests that the iPad Mini is, effectively, an iPad 2: an A5 with 512 MB of RAM and enough GPU power to drive the Gruber Display, but not a Retina Display.

Remember this when iFixit does their teardown.