I know that MANY people have been waiting for this. and its 6 days late but whatever
The package is released and accessible through Volume Licensing site. https://www.microsoft.com/licensing
And the docs can be found here:
Microsoft Lync Server 2010 Multitenant Pack for Partner Hosting is a unified communications (UC) solution for telecom and hosting providers. Unified communications is a way for telecom and hosting providers to expand their service offering to the present base customers. The Lync Server Multitenant Hosting Pack features include integration with Microsoft Exchange Server, Microsoft Outlook, and other communication technologies. Lync Server Multitenant Hosting Pack enables customers to manage geographically dispersed offices and mobile users in a way that reduces travel expenses, while maintaining highly collaborative team environments. This increased integration of communication channels translates to improved organizational flexibility that is often difficult to find in larger enterprise organizations.