It's not being sold as soy cheese, but rather as diet cheese, so it's actually available at quite a few delis and stuff -- I found it at my local Fresh Provisions, right alongside the gourmet cheeses. Best of all, because it's designed to be indistinguishable from dairy cheese, it has the same texture and, most importantly, melting qualities as cheese! It even tastes pretty cheesy. It does use regular rennet, though.
Anyway, it's by Eureka, and it's called "Mini Chol". It's packaged just like their other cheeses, so you can only tell it's soy if you scan the tiny label. It's around $30-$35 per kilo, so not cheap, but the same price range as any other gourmet cheese.