I don't know what it is with classic Doom games that inspires people to create such extraordinarily mods, but they just keep coming! A short while ago Brutal Doom got an update that allows you to use Doom 4 weapons, and now we also have Doom 4 Doom - a mod that not only recreates Doom 4's weapons within GZDoom (a source port of Doom), but also their upgrades and mechanics.
Naturally, this is still a mod so don't expect to see Doom 4 maps recreated within Doom 1 as that would simply take too long, but at the very least you're still able to turn into a demon and kick some serious ass! But enough rambling from me, just have a look at the recently posted video, its quite explosive:
If your interest is piqued and you would like to give Doom 4 Doom a try, head over to ModDB for the download link. For any problems or issues with crashing I would recommend you give this forum post a try and see if it helps you. And most importantly, do try and have fun!