When Flash is not installed on a system, a notice should show up telling the user to install it if they want to see the content. Currently with XF, there is no notice, just an area of whitespace where the video should show.
Using Ubuntu 10.04 with both Firefox and Chrome.
Screenshots of XF and Vimeo attached - ideally XF would show a notice like the one on vimeo
i guess the plugin code is not elaborate enough... and that is why no warning is shown...
it has become pretty crucial to have a message because of the growing popularity of Apple iPad (aargh!).
personally, i had love to see better support for HTML5 based video content. Both YouTube and Vimeo provide codes that is compatible with HTML5 that is supported by all the popular browsers (except for IE right now).
I have flash now, and you're right - I was posting that the message should be there so you don't get users who can't see a video when they are missing flash. It's not often you'd test software on a plain jane OS / browser combo