It is not simply grey. There are 4 shades of grey you can choose from, including a dark background to match apps like After Effects. In addition, all the tool cursors are new. Panels have been rearranged and modified.
If you think the only change was that it's grey, you are terribly mistaken.
I think that's more referring to making it truly customable. You know, those little conveniences I'm for instance used to in my 3D proggrams like creating custom toolbars/ tabs and giving each tool my own little icon. Not saying that the new stuff is bad and surely for 90% of the users this won't be relevant, but it would be nice to have some of that one day... And I'm also sure it implies removing tool redundancy so there is actualyl less, but more versatile tools...
I'm implying that they've really made a big deal out of what is a very minor change. It's become apparent from the last few versions of the CS Suite that Adobe are struggling to find new features for their apps. Consequently they are left to 'make a big deal' out of something as minor as changing the interface color and fiddling with a few panels.