New icons for themes?

[Gordon MacDonald]

I remember somebody posting (after 0.9 was released) that a new theme 
(modern I think) had been put into Mozilla. A couple of days ago I 
checked a nightly and saw some really pretty cool icons in the mail tool 
etc. However it was a little unstable so I didn't install. Now the 
change appears to have disappeared in the latest build.

What's happening with the new modern theme?

Cheers,

Gordon