...the ramblings of an IT Professional!
I came across this issue today when helping out a colleague of mine, where the owa virtual directory was created under the Default Web Site. On a normal Exchange Server 2007, this would be correct. However as this is an SBS 2008 server the virtual directory should be placed under "SBS Web Applications".
As you may know, there are two ways to force synchronisation in the Microsoft Online Directory Synchronisation Tool. The GUI method, which means you have to re-enter all the credentials and settings, or the PowerShell method.
If you read the Office 365 Deployment Guide, it will state that to support multiple top level domains you need a separate instance of ADFS for each domain. This can get very expensive in terms of hardware, as you would need to make each instance highly available. Typically this would mean four servers per instance, two ADFS servers and two ADFS Proxies servers in the DMZ.
This is no longer true as of ADFS 2.0 RU1.
Exchange 2010 Service Pack 1 Update Rollup 3 was the fix for the memory leak found in Exchange 2010 SP1. You can read more about that on one of my previous article's here. Unfortunatly that fix was removed on the 14th March 2010 due to the fact that the fix intrduced another problem with Blackberry Enterprise Server, more commonly known as BES.