“This will change the way you design websites. Add a line of code to your pages and choose from hundreds of fonts. Simple, bulletproof, standards compliant, accessible, and totally legal.” – typekit

While the pricing is kind of hefty to be able to do anything solid with it personally, this is a great option for companies that have the resources. $250 a year for a major company is a drop in the bucket. I think this will certainly enhance the web if it catches on. There are tons of font replacement options but all are far to cumbersome and weigh the page down too much.  The load of the font on the page is listed with each font. Some are as low as 50k or so.  I will definitely be trying this out as soon as possible.