Now that Service Pack 1 is out for over week, it's time to know a bit more about it's know issues, as well as work arounds, and the most frequently asked questions, or FAQ.
We can start by reviewing the mother of all questions :
The order of upgrade from Exchange 2010 RTM to SP1 hasn’t changed from what was done in Exchange 2007.
So, you should upgrade server roles in the following order:
On other question that I was already asked was :
When installing Exchange Server 2010 SP1 the prereq check may turn up some required hotfixes to install. The message will include a link to click for help.
Clicking this link redirects you to a page saying that the content does not exist.
We're working to update the linked content :)
Meanwhile, please refer to the TechNet article Exchange 2010 Prerequisites to download and install the prerequisites required for your server version (the hotfixes are linked to in the above table, but you'll still need to install the usual prerequisites such as .Net Framework 3.5 SP1, Windows Remote Management (WinRM) 2.0, and the required OS components).
You can find all the details about SP1 at :
You Had Me At EHLO... : Exchange 2010 SP1 FAQ and Known Issueshttp://msexchangeteam.com/archive/2010/09/01/456094.aspx
if you happen to have other feedback, do not hesitate to comment. It will help us improve even further in the forthcoming versions.