The latest version of Transmission is reporting availability as an Intel application only now. Firefox 4.0 is [officially] only available as an Intel app, and starting with 4.0.1 the download page is using the Finder icon in place of the Universal one.

It took five years, but it seems bigger players are now starting to leave the PowerPC legacy behind. I'll still be building for both for a while yet though, there are still a lot of souped up PowerMac G5s in use out there.