We'd like to enable end-users to be able to create and maintain their own email distribution lists in Exchange 2010, where those lists may include users inside the company but also customers, partners, etc. who are outside the company.

One of the limitations in Exchange 2007 (see this question) was that any member of a DL had to have an entry in active directory. You couldn't just take a group of email addresses (both inside and outside my company) and create an Exchange DL with those addresses without involving Active Directory admins to create entries for each external user. For a company creating hundreds of small mailing lists every month, this was an unacceptable IT expense.

So we had to use a separate mailing list solution (GNU mailman) for DLs which included external users.

Is this limitation relaxed in Exchange 2010 so we can throw away GNU mailman and use Exchange instead?