I can see it here (WinXP64+Firefox and Ubuntu 6.10+Firefox) and at work (Win2k+IE6 over Citrix) but not on the client PCs at work (Ubuntu 6.06 and 6+10+Firefox).
The latter has a different link to an ISP, and works with 'nearly all' other sites. (Someone with a similar problem has pointed me towards a Dutch site - www.geenstijl.nl - neither of us can get to work with no obvious similarities to live.com.)
It'll resolve to an IP address, and trying to access Hotmail will cause the URL to redirect to login.live.com/etc, but apart from that, nothing.
Annoyingly, live.com doesn't respond to pings from anywhere, so I can't use that to help decide what's going on.