First see here: www.apple.com/safari. Click on the “Graphics and Fonts” link on the left. Then read the 3rd paragraph.
With CSS3 web fonts in Safari 3.1, web designers can go beyond web-safe fonts and use any font they want to create stunning new websites using standards-based technology. Safari automatically recognizes websites that use custom fonts and downloads them as they’re needed.
Well actually no. Designers can’t just use any font. You know those fonts on your computer? They are considered a computer application at least in US law. They have end-user license agreements just like most software. And usually the end license agreement prevents you from distributing said software. Some fonts actually prohibit you from even embedding the font in a PDF.
So yes in a manner of speaking a designer can use any font in his website designs with Safari, but from a legal standpoint, no they can’t. Not unless the font vendor authorizes such use.
Now go check http://typophile.com/node/43971 to see what the type/font creating community is saying. No one likes their hard work given away without their permission. And this is the crux of the matter and why Apple might want to rewrite their marketing copy to more accurately reflect the reality of the situation.
Clarification: My main beef with Apple’s marketing text is that it conveys the perception to those who do not know better, that any font can be used regardless of the actual legality, licensing restrictions, etc.