There was a small glitch in the Sci-Fi Channel's airing of the Babylon 5 episode "Midnight on the Firing Line". It shows Commander Sinclair finding the raider's command and control... space teapot? The 16:9 version has more picture area on the sides, but it's also been cropped a bit on the top. Note that my videos are not cropped; the 16:9 version has a bit of the black letter-boxing visible. Clips are MPEG-1 streams, 512-KBit, 6.3 seconds, about 450KB each. I'm told these clips won't play with Microsoft software. Every MPEG player I've used in Linux can play them fine.

Update: I've used Real Networks encoder for Linux to make a Real Video version, which software challenged users (Windows users, this means you) can probably play. It's lower quality, but is only a measly 76 kB.
TNT 4:3 Sci-Fi 16:9
MPEG clip MPEG clip, RealVideo clip
[VOICEOVER] Sinclair: A C&C transport, that looks a lot...... like that?!

This scene from the episode "Survivors" looks a little squished in Sci-Fi's 16:9 version. It's my guess that the CGI for the 3-d video game wasn't rendered in 16:9, so they had to make do with the 4:3 footage. I'm surprised that they chose to squish it, instead of just cropping the top and bottom since there is nothing interesting going on there. After all, they cropped the entire pilot, what's this one scene?
4:3 from TNT 16:9 from Sci-Fi
Did someone turn up B5's gravity?
Maybe I spoke too soon about cropping. A couple epsiodes later in "Signs and Portents", they did just that. There is a scene where Morden has gotten off his ship and is walking down the hanger. The background is a very nice CGI scene with some ships and superstructure that curves up in the distance to show the roundness of the station. It loses quite a bit when it's cropped in the 16:9 version. The spots on the floor look like they are at a different angle, but this is just an illusion. If you overlay the two pictures, they are exactly the same except the top is cropped off.
4:3 version 16:9 version
Looks like there were a couple bloopers in "Babylon Squared". The first is mentioned in the Lurker's Guide, I think the second is a new one that shows up in the widescreen version.
Hmm, is that a Vorlon we see inside Garibaldi? No, it just the handiwork of a bored EFX guy. Why isn't this guy in uniform? And why does he look so bored? Sinclair just go thrown through the air after touching a guy in blue space suit who appeared out of nowhere.