As is so often the case with these sorts of posts, there are several issues being conflated here:
1. Growl authors want to ca$h in
2. Widely reported issues under Lion
3. Legitimate conjecture over rights and ethics for pmetzger's fork and whether it can be called Growl
I'd be more than happy to donate (more) to Growl, although I admit that the "suggested upgrade" made me pause. It felt like it crossed that slim line between a premium version and bait-and-switch that is hard to argue either way. It's certainly not strange that people are responding to the fact that this was just dropped on the existing userbase. That pmetzger is getting C+Ds (has this been confirmed) makes me really uncomfortable — it's not in the spirit of OSS as I understand it in my gut.
Ultimately, I don't think people will have a problem with paying, and certainly not such a small amount. It's more the way that it's been thrust upon us that feels slightly off. Am I right?
Of course, we haven't heard their side of the story yet. I urge you all to wait before you cast aspersions on them, because they've worked hard on something many of us have used for years.