We actually already support oEmbed -- the big problem with it is discovery. We have to hard code lists of sites that support oembed -- which really defeats the purpose.
oEmbed does have a discovery mechanism, though it's its barely implemented by anyone. 280 Slides implements the discovery consumer portion of the spec.
There's a handy 3rd party oEmbed provider for popular services that don't natively support it: http://oohembed.com/