I don't think I've been a Whedon fan long enough to call myself a sheep, but I definitely wish I'd tuned in sooner.
Whedon has a talent that manifests in ways not seen in a lot of other shows, and that is what makes his stuff so dear to us. Not only is it great, but it's unique. His ability to slice and dice and mix around genres is one of the many that gets me every time. So far he's created worlds of horror/fantasy/action/dramedy, sci-fi/western/dramedy, and just recently, the musical blog. And he's not done. The term genre exists for a reason: to generalize. Well Whedon just blows that term out of the water, in my opinion.
In addition to that, his writing is top notch. And this goes for his whole crew, too. I mean, refresh the Buffy Boards main page a few times. You'll get a quote that'll make you want to pee your pants, and you'll get a quote that'll sober you up so quickly, you'll feel bad for laughing in the first place. Approriate or innapropriate, his shows have got it all. It's these things, and so many more, to which we all react, even if we may not realize it. It's why he has this lovely cult following of the "helplessly and hopelessly addicted," as white avenger put it. So yes, we are all ga-ga over Joss, but really, who better to be addicted to?
I'll admit, I haven't experienced everything that he's made. I haven't watched the Buffy movie, and I don't plan to read any of the comics. Still, though, having said all of this, I think I'll deem myself a Whedon Ewe. Baa!