Having a 3 tier system for games, is something other have done. Take SW:TOR for example. You have the F2P level with restricts a lot of stuff. Preferred Level who were people that paid for content, and gets to use what they have already paid for, and then the Sub level which is complete open access.
I can see a benefit of that for Eve. A Middle tier that allows for users to use what they have already paid for, with the restrictions of Alpha.