[wp-hackers] How to fix oEmbed in 2.9

[Otto]

I'm very disappointed that the core team has decided to cripple the
new oEmbed functionality in 2.9 by intentionally disabling the
discovery mode and removing the option to enable it.

So here's the fix for this 2.9 misfeature:

add_filter('embed_oembed_discover', create_function('$a','return true;'));

You can add that into a plugin or your theme's functions.php file and
oEmbed will be up and working again, with full uncrippled power.

-Otto