I will watch them and likely enjoy them. It will be interesting to see where things go, and if he develops the world more than just visually. Though even if it's more excuse plots for pretty visuals and interesting world/creature design, I'm sure I'll appreciate it on that level. So long as that's on the same level, he can do 2, 3 or 15 sequels.
As for Middle Earth, I for one am glad that Jackson is having a hard time letting go! Bring on the Silmarillion! Or at least the Beren and Luthien storyline, because that would make a great film. I have no problems with the Hobbit as 3 movies, particularly since the Necromancer story was implied in books, but never really delved into. Also, in the Hobbit, the Battle of Five Armies takes all of a page and a half, which would not do for a film.
But I am first and foremost (and obviously, I think) a fantasy geek, so I'm biased there!