I've seen a lot of games recently being re-released with HD graphics updates. Wouldn't it be great if B did this for Morrowind?

There are already mods that make Morrowind HD/better graphics.

Unless you mean console version of Morrowind, then I see what you mean

I don't think there is any need. Just buy the PC version, crank up the resolution and use various usermade plug-ins, and you're set.

How has this become such a hot topic?

Unlike the Halo series the gameplay changes from Morrowind to Skyrim make an update implausible (unlike with Halo), they might as will release a new TES.

It's obviously Bethesda doing market research...

... or people refusing to read topics that are not their own.