In getting morrowind to look like this?

http://www.youtube.com/watch?v=6OvA8stLwco

assuming I bought a brand new mid range desktop tommorow?

You then need to download all the mods.

Thats a powerful rig. I'm guessing custom built to be powerful.

Yeah ofcourse mods.. but in terms of hardware?

The video was 2009, so things may have changed a bit since then. But you're still going to need a fairly powerful rig. Mid to high end Phenom at least. That spec with 16GB RAM and an Nvidia GTS 450 handles Morrowind Overhaul pretty smoothly.

I have 10 GB RAM, Intel i5 and ATI R 4770, so my graphics-card ain't that hardcoe. Although my mw setup is way better than in that video

6g ram. Serious...? You don't need something that powerfull. Even a 10g ram is pushing it.

isnt anything more than 6 gb of ram sort of pointless, you might as well go for faster ram than more of it.

Because Morrowind is a 32-bit application it can't take advantage of it.

I do have Corsair Dominator GT 2000 MHz so they're pretty fast..

Anyhow, no you don't need that lot of ram for MW. I think it's much more based on your CPU. So a good CPU will do wonders!

I mean even for any game, more than 6 doesn't do much, not even for crysis

Not entirely true. Even if patched (with 4GByte patch) Morrowind can't see more then 4 GByte on a 64bit OS, your OS file system cache can, it is very noticeable after first loading especially if you are loading many mods
[EDIT]To clarify things, you don't get more FPS, but faster loading times

You do know that a Sempron is a budget processor, don;t you? It's the same as the Celeron of Intel. Sempron is actually an Athlon, but then with locked cores, half of the L2 cache.
I assume you mean Phenom. Although a Sempron isn't bad. Can handle Morrowind though.

Yes, I did...

I can get pretty much the same as the video and better on an Intel i7 2600k overclocked to 4.8GHz, 8GB of G.Skill Ripjaws DDR3 1600MHz RAM, (Overclocked to 1833, or something around that...), AMD Radeon HD6950 (2GB vram) with the BIOS mod to unlock the 6970 shaders, and a 7500rpm Seagate Barracuda 1tb drive. The other specs don't affect it as much, I think. In my opinion, the Processor speed and architecture is the most important, then GPU speed/capacity, then RAM speed (if you have at least 6 gigs already).

I can't wait until Aedra is finished so that I can take advantage of all of my cores/ ram.......

To answer the op, the CPU is also very important.