I have a MAC book pro and I use Bootcamp for WIndows 7. I will admit, and I'm not sure if it's Bootcamp specifically, but audio quality is lost when comparing something being listened to through the MAC end as to the W7 end. Not sure why this is, however.
So far I've read about people wanting I-Doser to work on a MAC but complain about not accepting .drg files in iTunes etc.
To that I say, just buy the Premium I-Doser application. You can then export your doses into MP3 formats.
I'm not sure if exporting it to an MP3 format losses some quality, which I can imagine it must, but pretty much all information is retained. The file sizes are quite big after export.
This allows those without an iPhone to load the MP3 files into iTunes and stick on your iPod.
Much quicker this way.
Though I will admit, if the devs can make an iPhone application, then it wouldn't 'strain' them too much to make a compatible version of I-Doser for a MAC.
Please consider it.
You've got the market for it, why not just develop it? You'll make your money back.