I'm not saying Microsoft has to step up again. In fact it's unlikely they will. They've got some beautiful new fonts that shipped with Vista (and to the consternation of the Vista product managers, the latest version of Office as well). But while one can get these fonts freely on the web, they will never be widely licensed for distribution.
But what I don't understand is why others haven't picked up the slack here. There are some really nice free fonts out there (many of which have been featured on Smashing Magazine) that could easily be included in the Firefox distribution—like these for example.
Or how about Adobe? They have amazing reach with both Flash and Acrobat Reader, and they also have an amazing library of typefaces. How about it Adobe? How about picking up the slack here and giving a bit back to the Internet community that made you the powerhouse you are today?
Or Google? They licensed the Droid fonts for their Android phone platform. How about extending use of these fonts to computers as well? They've got plenty of client installs (Google Desktop, Toolbar, Talk, Pack...) they could bundle fonts with.
Ah well, I'm not holding my breath. I'm still going to use SIFR for my designs. And for the love of everything that is beautifully designed, I encourage you all too as well.