This is carrier dependant, but the Mini has this feature and works fine.
Two limitations, compared to other hotspots:
1) You cannot rename the hotspot/SSID,
2) The password is displayed in clear, in the Settings of the iPad.
My carrier is an overseas provider, and initially the Hotspot feature did not appear. However, after a short trip away (in Airplane mode) the feature appeared when cellular was reactivated. (Don't know if this was related to the simultaneous press release for launch of iPhone 5 in my region?)
Anyway, it works and is easy/reliable to initiate.