Microsoft released the Quick Start Guides for Outlook Voice Access 2010 (OVA). Like the Quick Start Guide for Outlook Voice Access 2007 (available here), these PDF guides contain a reference sheet showing the Exchange 2010 Mailbox Unified Messaging navigation system and options. The PDF has two pages, one for Touchtone Access and one for Voice Access.
Because Exchange 2010 UM Voice Access understands several languages, some localized versions of these guides are also made available. At the moment guides are available for: Germany, Austria, UK, US, Spain, Mexico, Canada, France, Italy, Japan, Korea, Netherlands, Brazil, Sweden, China and Taiwan.
You can download the guides from here.