The official patch notes from Blizzard's site (http://www.wow-europe.com/en/patchnotes/) are quite "light" taken into account what changed.
But that isn't my point, more of things I found out that surprised me and I'll explain you why. I'll add up more as I find them as yesterday I mostly had the boring experience of creating all glyphs for all my lvl 80 toons I want to level in Cataclysm. I'm halfway but it's something over 5k Inks ^^.

1 - Mining and Herbalism are giving XP. I knew it was coming for Cata but was really surprised to see it now! Awesome;

2 - Transmutes still have CD. It's nice, prices will still be high . Not sure about procs though and if it's still worth speccing my 9 alchemists to transmute since I believe it'll go away in Cata - thought it'd be gone this patch. What do you think?;

3 - I've noticed on the spell book you can buy azeroth fly (not fly for sure, of course). Someone did it?

4 - You can track both minerals and herbs at the same time (maybe even more stuff afaik). I was doing that in beta but I thought it was just to easen up testing! Is it a bug? I just love it on my Paladin dual gatherer .

5 - I feel the process of logout and exit game to be of a really improved performance. Am I dreaming?

6 - My latency was halved (and it was patch day). I was at 33 instead of the usual 70-75.

7 - Everything seems so much more "fluid" in terms of visuals and input reaction. I was tired and bored, that might be it .

8 - My inscribed had already learn everything from glyph books but just to try it out I did it again yesterday and there was a new glyph to be learned (after learning all others from trainer).

More will surely come of course and I hope to get feedback from you.
Cheers and a good day to all,
A.