Most the designers I work with use Adobe fonts. Having an easy route to implement the fonts I actually encounter day-to-day is a huge plus. I’ve wanted to use typekit in the past, but haven’t, because you ususally have to make the designer and client compromise on a lesser known font. Perhaps the next project I work on I can get by without Cufon or sIFR. It’s nice to see how quickly @font-face typography is gaining traction (finally!).