Depending on how you want to define a "completed item," there are literally a dozen cds worth they could release, and then they could decide what to do with the rest.
Lots of stuff, though some of it would be for collectors only, such as a whole cd of complete takes of an evolving arrangement of "I'm A Man," etc.
There is rumor that there will be another box set with different content later this year.
Those earlier ones were "definitive," for the Experience Hendrix then under Universal. Now there's a new deal and they'll want to get money from the core catalog for the new partner.
No one is definitively saying that they will be any different. There's a lot of hope from the Hoffman community that they be remastered by someone else, with no compression, limiting, etc. I think this unlikely to happen, and I'm happy if Kramer remains the engineer, especially for the mixing and Marino does the mastering. If they were to be a little less loud, wouldn't hurt. We'll see.