I love the DOOM series. I'm going to buy a DOOM complete pack on steam soon. I am curious though. With the older games now being made for digital download and compatible with new operating systems, have they added the ability for the game to scale nicely to a 1080p monitor? Or is it gonna look like a stretched, mangled loaf on my nice monitor?

Buy the doom pack to get the data files you need, then replace the engine with a modern source port. I suggest http://vavoom-engine.com/. You get direct3d support, dynamic lighting, all kinds of improvements over the original engine.

But you need the WAD files from the commercial games to run it.

Fantastic sir, thank you.

You should check out GZDoom as well - very very very fast though with less bling than Vavoom and Doomsday.