well, the next obvious question is --- the youtube ID still unique?

if so, the domain/sub-domain wouldn't matter anyway..

no ?

example:

http://ca.youtube.com/watch?v=6hoiRLzqhug

http://www.youtube.com/watch?v=6hoiRLzqhug

same vid -- so i see no harm in just eating the URL up and using markup to the most logical sub-domain for the board..

only real issue might come in where the board is all over the map and diff sub-domains might be diff for diff users laugh

if you get my drift..