The thing is.. I doubt it's because IE is simply incapable of displaying those videos. Say all you want, but before I started using Chrome, I can't remember any big problems IE had. Sure, display errors like I've posted here before (and it still seems to have), but no things that simply didn't work at all. IE doesn't have a problem with Flash in itself.. What codecs are those GameTrailer videos using?
Look at this page:
http://ie.microsoft.com/testdrive/Graphics/VideoFormatSupport/Default.html
Everything works there. Perhaps there's simply some IE specific code missing from you ehh code?
[link]
Edit:
Fact is, the above video (and I assume the ones you posted as well), simply works when viewed on the Gametrailers site, on IE 9 & 10 (and I could test 5, 7 and 8 as well). So it must be something in the embed code..
It's been a while for me, looking at code . Had to do some googling, how about that. I still don't know the specifics, but it seems to be an object vs embed thing.
Solution:
Get the embed code out of the object code nest. The object code still won't work, but the embed code will.
Edit:
Final comment:
Using the embed code in itself, it works on IE 5 / 7 / 8 / 9 / 10, Firefox 4, Chrome 10, Opera 10.
The object code, on the other hand, doesn't work on any of them. So there lies your problem.