Simple question, tough answer.
Fallout is famous. It's remembered. It's hailed as a great RPG.
Now, will the third game be remembered? It's my one, personal thought, that keeps me from succumbing to cynism, that it will be forgotten, unlike Fallout 1.
That this mediocre FPS/RPG hybrid will be lost to the sands of time, while the original cRPG remains in memory of gamers world-wide.