Is there an Overhaul mod akin to the amazing Morrowind one?

The best anyone can really do are texture overhauls. Morrowind was able to get such a face lift because Bethesda basically gave the OK for people to dig into the engine.

I'm sure that when NV is older that they will allow people to tinker with things a little more
love the Sig btw

There aren't really any compilations.

For textures, there's http://newvegas.nexusmods.com/mods/43135 (in several variations depending on just how powerful your PC is).

Also check out http://newvegas.nexusmods.com/mods/39856 and http://newvegas.nexusmods.com/mods/38285.

Also, another must have is http://newvegas.nexusmods.com/mods/42551. Also, check out http://newvegas.nexusmods.com/mods/39755 . If OJo Bueno textures are too demanding for your pc, you can try http://newvegas.nexusmods.com/mods/42028 , a collection of ALL the Ojo Bueno Textures reduced in size and optimized for performance!

Thanks guys! What's the Neat Clutter retexture?

Bethesda didn't explicitly give permission to dig into the MW engine, nor forbid doing the same for FNV. MW is an old game and it is easier to make dramatic improvements visually.

You can change shaders with FNV, just like MW. You can replace meshes and textures. However, the game isn't that old. I don't there is as much of a need to overhaul all the graphics.