I have just upgraded to the 9900 and of course until the release of the new Theme Studio, themes are not gonna make much of an appearance.
The stock icons are OK, but nothing special, though easy to read and are functional.
But I have found some clean, HD, smart and colour icons courtesy of MMMOOO with their "3D Icons - Hard Candy Blue" theme.
A good start - and hopefully things will get even better when the theme builder becomes available to you (cleverer than I am) designers.
Here is the theme on >> APP WORLD <<
for those who want it, and it costs just £1.