Piece of crap. I was annoyed because of browser detection in general, and specifically I thought Camino is never going to take off when you can't even get past a gate like this. So I tried to open the site in Firefox 2, Firefox 1.5, and Safari 2.0, and I see the same damn pop-up! MSN Video was made directly Mac compatible a couple months ago, switching to Flash video, but it looks like someone can't figure out how to do browser detection, let alone get rendering engine detection right.
Update
I configured the site last night to use Google Analytics and after I created this post I logged on to cruise the reports. One thing it reports on is Flash versions, and I went to see how many were out there. Quite a lot actually, I am seeing at least 10 different versions, with 9.0 r28, 9.0, and 9.0 r45 making up 78.98% of my current traffic. 9.0 r45? I vaguely remember seeing 9.0 r28 installed, *gasp*, could I be behind the latest? Sure 'nough, I am, 9.0 r45 is available, I install, and now I can see the MSN Video! In Safari 2 no less. WTF? I know, Step 2 in the MSN troubleshooting steps was uninstall and reinstall Flash, but I knew when I saw the pop-up I had Flash installed and it it working, I was using it on another site like 5 minutes before the MSN Video thing. I guess the title on this post is misleading now, it should really be MSN VIdeo's dodgy required components detection, because if the latest version of Flash is required to view your site, say that. Also, this is the first time in a long time I have ever had to update Flash to view anything on the Web.