Along with the other points made in the Mashable article,
These are important issues to take into consideration when you use fonts in your own designs. Just because you can use a script font to display your primary content doesn’t mean that you should. Save that for headings and accents, keep main content readable and clear.
What if the user doesn't allow/can't process client side scripts? Or if you use the example below and Google's site goes down or is slow loading?
Quick example from Google's Getting Started - Google Font API - Google Code
<link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Tangerine">
font-family: 'Tangerine', serif;
<h1>Making the Web Beautiful!</h1>
You do realize that Google's own Site Speed report will tell you to condence your CSS files and reduce external requests, right? Kind of ironic don't you think?
I'm already noticing sites I Stumble that load then their font changes after the script kicks in. Really distracting.
As with anything new on the Web, thinking this needs some kinks worked out first before one jumps on the band wagon.