Very cool! It must have been fun to watch that all play out first hand. I was in High School still, unfortunately. I was definitely a PointCast user, though. Although it didn't turn out to be revolutionary, I certainly found it useful.
The thing that probably had the biggest negative impact was rewriting the client in COM (who remembers that?), this gave us absolutely no new features and bogged down client development for six months, meanwhile portals became the new hotness.
There were some interesting developer issues that we tackled back then, like using the i/o completion ports model (rather than the more traditional BSD sockets model). Since the servers were all NT the i/o completion ports made the code hard to debug but resulted in very high performance. I think (if memory serves) MSFT got that from their VMS roots. Some of the kernel guys on NT were bigshots at DEC (http://en.wikipedia.org/wiki/File:Vax780_small.jpeg)