- Linotype/Monotype: http://webfonts.fonts.com/
- Bitstream: http://new.myfonts.com/info/webfonts/
- FontFont: http://www.fontfont.com/opentype/
- TypeKit (various foundries): http://typekit.com
…and Hoefler & Frere-Jones is currently working on a web font licensing system as well.
Maybe in another year or so things will have improved to the state where more typefaces are available for online use than not.
Perhaps, but are any of them commercially reasonable yet? Pretty much all of the ones I've seen require either ongoing payments and/or third party hosting, or an up-front fee that scales with the (anticipated?) number of page views. As far as I can see, no-one else providing a related product/service gets these kinds of terms: would you pay a monthly fee for a piece of clip art, or a higher licensing fee based on how many times you wanted to print your annual report on paper?