Typekit is more than just a text replacement technique like sIFR/Cufon.
It's a subscription service that takes advantage of @font-face (new to CSS 3). @font-face basically allows you to specify which font to use on your website by specifying the file, rather than just the name. Obviously this will mean you can upload and use any font on your website without the need for it to be installed on others computers.
Welcome to Design Forums, thanks for posting your thoughts on TypeKit, and your link, found the article very interesting, I think as you mentioned, the one drawback I would be most concerned about is;
The second major issue is that you are relying on a 3rd party. If the Typekit servers are taken offline for maintenance or are loading slow due to traffic the best case scenario is that your website eventually loads with a fallback font like Arial.
That's a very good question. I don't think there is a solution. They could have an automated service where you upload a design to preview it in a font before purchasing, either as HTML or even a PSD is possible. Not ideal but the best solution I can think of.
with @font-face coding in css3 but you, y need font permissions to distribute and use (freeware fonts can be the solution) because youÂ´re just liking the font face located in the server using CSS file everyone can acess it and download it - more details: In the Woods – @font-face and 15 Free Fonts You Can Use Today
I would be very careful with what fonts you use. You can convert any font ready to use with @font-face (see font squirrel) or Cufon (see here) but unless you have a license for web-embedding this is illegal - so do it at your own risk!
Most fonts are not provided with the right licenses yet so make sure you find one that's free (for all uses) from a site like fontsquirrel.com.