OEmbed - embedded representation of a URL on third party sites

I worry about discovery, though.

"oEmbed providers can choose to make their oEmbed support discoverable by adding elements to the head of their existing (X)HTML documents."

So... I have to download the page, parse the link for oembed, make a request to the oembed service and THEN I can finally get the info I need to show the link?

I assume you'd only want to make this call once and store the result, so it's not -so- bad, but... That's a bit much. Of course, the alternative is to store the format for the service call for all major sites. (At least, as things stand.)