I don't think that this ROM for Leo is a real WP8 ROM. Infoscreen and Marketplace looks a bit different on WP8. (e.g. screen resolutions is missing in infoscreen and win WP8 marketplace is called store). I think ansar has done some registry editings, maybe bit more, and now WP8 marketplace is available in WP7.8.
Just look at this if you don't know. It's possible :
WP8 can't run on HTC HD2 and it's clones (HTC Mozart, HTC Trophy) = LIE