No. I still own the original, and it can be gotten for $5-$10 at any used game store. Why would I pay $40 to play it just with updated graphics? Besides, I don't feel like giving any money to 343 because until I see more details on Halo 4 I'm going to assume they're untalented and are just going to screw over the Halo franchise; a franchise which, despite the widespread hate for it, I've always loved, because the first Halo was what really got me into gaming. Especially after Microsoft's comments about how ODST and Reach had lost focus and all the games should be about John-117, which I thought was really narrow-minded. Reach was by far my favorite Halo game, and I loved ODST as well because it tried something relatively new for the Halo franchise.
So, no, I won't be buying Halo Anniversary or Halo 4. Halo ended with Reach.