Well, the branding for Mac Office uses Segoe so it makes sense to keep that brand consistent across all the pages. But it was more of a rhetorical question, wasn’t it?
But Pierre has missed that the text is not displayed using a font specified by the stylesheet (he notes that he doesn’t have Segoe installed). What actually happens is it is rendered as canvas elements, one for each word.
This screenshot shows how well it works for large size text and poorly for the small text (taken in Google Chrome dev version). I’ve selected part of the text to demonstrate that it is “live”:
Pierre is right, the smaller headline text does look terrible for the very same visitors Microsoft wants to sell to. But I don’t mind too much because the whole site is much less of a useability nightmare since the re-design. Microsoft’s Mac Web designers aren’t entirely evil.