Regarding the icons:
I seem to remember Ben saying he would like to move to.. I think he said vector icons, or something on those lines because bitmaps will appear too small on big resolutions. I don't think the number of colours will change for a little while but at least we're not still on the original 4 colour icons :-P So yes, I believe the icon system is going to move on, just not in the first OS4 release.
Each icon atm can have upto 256 colours &, correct me if I'm wrong anybody, these can be independant for each icon can't they? That should be enough for any self respecting icon.
On to the image... What a beauty! Everything just looks sharp, the 'default' GUI look is comin on very nicely. Not many complaints about that lately.
As ever, I'm just really looking forward to OS4.
Time for my entry into the os.community thing me thinks.