I can, i've toyed with this for a while. I just have a free vimeo account, so if I embed videos to sites, it only plays back in standard definition. if they want to view it in HD they have to go to the vimeo page itself. I'd have to upgrade and pay for Vimeo Pro. I figured, most people on the site are coming to see their video again, so them leaving the page isn't that big of an issue.
The one instance where I did embed a video was the front page with the demo. I wanted that embedded so i took the risk with it not being in HD while their on the page