Typekit, purchase, rental, DRM, etc .. it's all good, but here is an idea that can be easily implemented right now and that will cover the 100% of the web design community needs.
An online service that for a monthly fee allows rasterizing unlimited amount of text in a specific typeface. You select the typeface, the size and the color and it gives you a transparent PNG back. Licensed for a web use PNG that is.
If you think for a moment how exactly non-standard fonts are used in the web design, it will immediately make perfect sense. They are used sparingly for headers, menus and such and they are always rasterized. The web designers need the PNGs, not the OTFs or TTFs. So sell them just that.
If the service fee is reasonably low (something like $10 per year per font, or perhaps $50 for the buffet), this will open up existing font portfolios to a much much wider designer audience. It should also curb the piracy to a certain degree, because people are stealing fonts predominantly for the online use.
Additionally, this should allow for using custom rasterizers that are font- or foundry-specific. Case in point - Effra from Dalton Maag.
MyFonts, for example, already have all the technology in place to make this happen. Just needs a trip to a lawyer and a web interface. It all can be up and running in a matter of weeks.