Well, I thought this statistic might counterpoint the news of Netscapes final death, and I'm in an odd mood at the moment.
As we might end up cloning large parts of the Internet Explorer infrastructure someday, it's worth knowing roughly how much Microsoft invested/lost on it:
$1.25 billion dollars
This is according to Robert Scoble, who is an "evangelist" for Longhorn/Windows, so I expect it's mostly accurate.
The figure sounds somewhat stupid, a pinky-to-the-mouth Dr. Evil moment. If you consider a large team of programmers working on the product for many years however, it becomes quite believable. Consider that IE encompasses not only MSHTML, but also things like MLANG, shell integration, ActiveX, probably elements of WSH and so on.
I hope somebody finds web browsers interesting around here ;)