wow, you really did a great job!

But you're right. On big wide-screens there is a bit too much room left. I have a 24" with 1920x1200 for example. Some ideas how to fix this a little:
-I think that on the right there are a lot of elemtens, like the icons, albumart, spectrumthing, tracknumber bitrate and volume. All these things are in the last 15% of my screen. So I suggest that make a little bit more room between them. It would be even nicer if this would happen regarding the vertical size of the player. So if you resize the window not only the gray field in the middle will change.
-Another thing I just noticed is, that the words "Title", "Artist" and "Album" are a little bit too small. It's difficult to read.
Some other things:
-IMHO a stop-button is important (also for new users of MM) but it don't have to be big. I really like how it's done here:

-It would be nice if there would be a semitransparent white 1px-frame around the album art.
But again: Great work, morten! I think this new skins is something very important for MM3.
Big_Berny