The guy even said if you had 200 different businesses, you could have 200 separate accounts. The only rule is, that whatever email you have as your 'Google Account' (ie the email address you use for the adwords account/youtube etc) should be tied to only one adwords account. Provided you have a fresh email for each account, you're gold.
Just thought I'd share that with you guys. It's funny what you can find out with a simple phone call :-)