The window theme I'm using is kind of based on the SilverGreen theme from OS4.1.1, I'm using the Blue version at the moment. It's one of Rebel's Workbench theme packs for VisualPrefs/Birdie/MUI. I'm running OS3.1, but these themes work in OS3.0-3.9 as well.
Also, I think a bounty to maybe get IBrowse open-sourced might be nice. While CSS support is unlikely, it's still a great browser for viewing the websites that do still work. Also, if you open IBrowse on a Super High Res Interlace or HighGFX screen, most websites fit fine. Since netbooks are so popular these days, the average screenwidth has dropped to 1024 again so website developers are being encouraged to design their sites to scale or fit.
I've never really been interested in towerising my A1200 or adding a graphics card. I figure if I want a 24bit RTG Workbench I can just use Aros and Amithlon on my PC. I like sqeazing everything I can out of the original chipset anyway. Besides, we'll have the Natami soon!
And speaking of the Natami, and also the MiniMig and FPGArcade, they all will run OS3 so the market isn't disappearing, it's growing! And of couse there's WinUAE/AmigaForever.