This branding makes sense. Moving the enthusiast range on a different socket to it's own brand. It's a bit confusing currently that you can get an i7 on both mainstream and enthusiast sockets.
Bearing in mind that the i7 brand came into existence on the X58 platform with Nehalem. There was a reason for the i7 name (something to do with 7th genuine architecture mix up since they went back to pre-Netburst or something, can't remember exactly now), whereas the i5 and i3 were tagged on as afterthoughts in branding.