Well, it looks like http://www.gamesas.com/bgsforums/index.php?showtopic=1014824&hl=water, probably used with ENBseries enhancements, and a nice water shader.
These sort-of visuals are common place if you have a PC that can run it all.
Hi, i' King_Pix, the author of those videos. =D
No, there isn't ENBseries, it's the TrueBloom g5 edited! That's a complete morrowind Graphics & Sounds Overhaul pack that includes over 100 mods of textures/Models and sounds, installable with 3 clicks! Now it's only in italian, soon in english!
PS: Sorry for my english >_>