The trailers for the first two Diablo games were superb for their time and really helped set the scene with some hellish imagery. Diablo games are meant to be dark and foreboding and the Diablo 2 intro cinematic helped set that tone perfectly. Now it looks even better thanks to some remastering work.
The Upscale Youtube channel has posted this great revamp of the Diablo 2 introduction cinematic. This remastered video also includes side by side footage comparing the original cinematic with this remastered version. There is a real difference in clarity and definition as you can see below in the video.
Blizzard may not be able to bring the complete game of Diablo 2 up to modern standards as we now know, but at least this trailer brings an improvement to the cinematic. All that needs to be done now is revamp the superb LoD cinematic redone and the job will be complete.