Even in this modern world of HTML5 there is still a very strong case for Flash Video playback (after all its still the option of choice on YouTube), the only problem is when you play flash video inside a Virtual Desktop session (VDI) the servers CPU can quickly be chewed up and so ruin the experience for everyone.

The simple fix here is to use Citrix HDX Flash redirection and a compatible thin client like the 10ZiG 8848c (Linux powered) or any number of the Windows Embedded Standard options out there.
In this situation the flash video is rendered on the thin clients processor and with more powerful (but power efficant) CPUs becoming available in thin clients all the time you can expect a nice smooth video playback on your endpoint device without hammering the servers CPU.