We've made several enhancements and bug fixes based on community feedback.
Please go to our Mailbox Server Role Storage Requirements Calculator updates tracking page to see what is in this new version!
A blog post explaining the calculator is here and or you can download the calculator directly.
Read my favorites blogs:
Designing a backup less Exchange 2010 Architecture
Step by step guide for upgrading Active Directory from Microsoft Windows 2003 to Microsoft Windows Server 2008
Microsoft Exchange 2010 CAS Array – Steps and Recommendations
Appear Offline in Microsoft Office Communicator Server 2007
Microsoft Exchange 2010 Test cases
Microsoft Exchange Server 2010 Disaster Recovery
Microsoft Exchange Server 2010 Upgrade Guide