Yes, Toast Titanium 5 is OSX native. Yes, the new version of Jam is OSX native also.
The problem is, for those of us who already own Jam 2, and know what a time-saver it is on getting your audio CD "just right", with regard to crossfades, and audio between tracks, etc. are getting SCREWED on the price!
If you already own Toast 5 you get to buy Toast+Jam (Plus Peak LE VST) for $99. That's a good deal if you only own Toast 5, but if you already paid $200 for a previous version of Jam (and also already paid for Peak LE, like me), it SUCKS!
Roxio is not offering an upgrade path for current Toast and Jam owners. (I asked them via email.)