Yes, there will be remastered versions of ESB and ROTJ.
As to the HTPC, I for one use my PC for most of my movie playback. I pretty much only use my BD player for bonus discs with complicated navigation (since I use MPC-HC for BD playback on PC and it can't do menus) or when my PC is busy doing something else, like rendering. I love all the options I get from PC playback - I can shift 2.40:1 picture higher or lower on the screen according to how I'm currently sitting, to keep it in my direct eye-line. I can zoom in and out as needed. I can change subtitle placement font and size, which is always great, because I usually find BD sup subtitles to be annoyingly large and I usually prefer for them to be in the black bars. I can take a screenshot whenever I want. I can search through the film using mouse, so that I can jump to any time in the movie with a single click - it is just generally more flexible.
And I can do this: