I like how all three threads in the "Sequels" forum are sort of Star Wars-related, since two deal with Abrams departure, and one is random as hell.
Honestly, I think it depend son how fast Disney expects these sequels (also, so far Abrams is on VII, but it isn't certain he'll do the other Sw sequels.) Remember, the SW OT had three different directors, so I wouldn't bet the farm yet that Abrams stays on for the entire trilogy, but if he makes a good VII, he may be kept. Its all about how Disney does business. With the rumor two other writers are already drafting the other two sequels, and Disney talking an SW film somewhere between every other year and every 2-3 years, they may want someone working on the sequels while Abrams is finishing VII, and he may not carry over.
tl;dr I wouldn't count Abrams out, but since Star Wars is supposedly his dream, he may stick around. time will tell I'm sure.