So if you want to be totally up-beat or perhaps are testing out Boxee then you will want to install the latest Adobe Flash Player (Boxee actually seem to require this), but no worries you can get it right here;
http://labs.adobe.com/downloads/flashplayer10.html
Among other things this version will add HW acceleration, neat for Netbooks as compatible GFX cards now can assist in playing video and thus perhaps adding HD playback to your otherwise slow Atom processor (however this DO require a compatible GFX card to work like the Nvidia ION and others).