Indeed - and I specifically asked the sales person what file storage the Nexus 7 uses, if Macs can natively read it, if any part of the software / firmware is Windows-specific, if I'll have to download and install a driver, and he told me no. If he didn't know, that'd be fine; it's that he was positive that it would work "out of the box" with a Mac that bothers me.

In any case, I don't mind having Android File Transfer on my Mac - but Google really does need to make it clear that Mac users will need to download it. As far as Linux is concerned, I didn't even see a "download for Linux" link. (Though I could have easily missed it, as I wasn't looking for Linux.)