Great! Only a couple days after I bought a license for YummyFTP too. :/ Transmit 3 looks amazing so far. It looks like I'm going to be upgrading soon.
As someone that has owned and used Yummy for a while now I can give you a little encouragement:
1. I think that most of the new features of Transmit were already in Yummy! The only thing that jumps out as not is the tabs.
2. Yummy is being activly developed with betas put out so have no fears about it falling behind. It is a great product and also works with textmate. In fact I have both Yummy(local and remote) and Path Finder set so that if I hit Command-B it opens in texmate.
Sincerely,
Eric C