Fuji's E-6 line will die mainly because of two reasons (MHO)
1. Fuji's Marketing department - no one seems interested in selling films
2. Availability of chemistry - with Kodak E-6 chemistry supply drying up (available in large packs not feasible to use for small volumes), There is no alternative for the labs. With Kodak's distribution network, Fuji never had to worry about selling chemistry. Now I don't know if they will be able to put up an effective distribution system in place or even be interested in doing so.
just my two cents