The article you quote there is exactly the one I discussed on the Boing Boing G+ Group (tl;dr: David Lowry doesn't math so good).
I might also point out that if Lowry is relying on broadcast royalties to survive, he's going to starve to death, Pandora or no Pandora.
I love Pink Floyd to death, but the authors of "Have a Cigar" have made packets of money in the recording industry while remaining pretty clueless about it's workings. I don't hold it against them: I would expect my grandparents to understand iTunes either.
There seem to be two questions that are floating around:
1) Should Pandora pay a comparable amount to other broadcasters?
I would have a hard time explaining why they should pay more.
2) Is Pandora paying a comparable amount to other broadcasters?
That depends on radio listenership, which is a closely guarded secret (well, I can't find good numbers), but my reasonable guesses suggest that they probably do.
Neither of these addresses the fact that if I were a musician, knowing my own musical purchase behavior, I'd do everything in my power to get my tracks on Pandora, whether I was being paid or not. I think it's hands-down the best way to discover music: essentially it's everything radio should have been.