sometimes when a video clip is posted on the TouchArcade front page it wont play on the iPod Touch claiming it's a flash item. seems a bit ironic some videos play and others dont on the Touch.
Weird, any video in specific? We are kind of at the mercy of YouTube when it comes to encoding and offering iDevice-friendly videos. I know I've come across a few random ones in the past that weren't available on my iPhone's YouTube viewer app. What you're probably seeing is an embedded video that we didn't take ourselves, and therefore wasn't uploaded to YouTube. Videos from sites like GameTrailers.com, for example, will just show up as a flash object.
I think when you upload the video it there's an option for like if you want to to apear on mobile devices. I'm assuming that that option is off thus making you not able to see it. Also like someone else said it could be a flash player.
If it's a video from Vimeo (usually from ngmoco) it won't work. If it shows the YouTube box thing but with a line across it, it means YouTube is slow, video not yet iPhone compatible.
Yeah this happens on every newly embedded video on all websites for me anyway. I just check back in 15 min and it's good to go.