This article over on The Three UC Amigos blog gives a great comparison of OCS 2007 R2 vs Lync 2010, both on-premise & Online versions: http://blogs.technet.com/b/ucedsg/archive/2010/11/09/should-i-deploy-lync-server-2010-on-prem-or-wait-for-lync-online.aspx
Category: Office 365
Great collection of Office 365 resources
Brett Hill has put together a single page where you can find links to information about Office 365 from the various sources around Microsoft (eg. Office Help, Office365.com site, Microsoft Downloads, etc.): http://brettblog.com/Office_365_Resources.aspx