And you can also subsciribe to video feeds via video center which should be in your application manager installable applications. I have that tekzilla small xvid feeds and it works well in mplayer for sure.

I SPECIFICALY TESTED THE GMAIL VIDEO YOU LINKED HERE AND IT WORKED WONDERFULLY ON MPLAYER. I DOWNLOADED THE XVID SMALL VIDEO AND IT WAS A TREAT TO WATCH ON THE GORGEOUS SCREEN. mAY BE THE LARGE WILL ALSO WORK.