Jason has written a great post on why Exchange Server service pack 1 affects mobile users. Summary below or go here to view the full post:
There are many key enhancements in Service Pack 1 however from a mobile perspective there are some very important additions.
With Service Pack 1 we have added 30+ new policies for Exchange Activesync. These new policies will require a future version of Windows Mobile (similar to System Center Mobile Device Manager 2008) however they can be implemented within your Exchange 2007 environment now ready for when that version becomes available.
There are 2 different categories of policies - the first set control the Sync, Authentication and Encryption settings. The second set are really focused on controlling functions on the device.
Within the Synchronisation setup we have the ability to configure many of the synchronisation options on the device: Configure message formats (HTML or plain txt)Include past email itemsEmail body truncation sizeHTML email body truncation sizeInclude past calendar items (Duration)Require manual sync while roaming
With the device password we can enforce more complexity as well as setting a password expiration and remembering password history Minimum number of complex charactersEnable password recoveryAllow simple passwordPassword Expiration (Days)Enforce password historyAllow Windows file share accessAllow Windows SharePoint access
From a security perspective we can control the use of SMIME as well as whether Device Encryption is enforced Require signed SMIME messagesRequire encrypted SMIME messagesRequire Signed SMIME algorithmRequire encrypted SMIME algorithmAllow SMIME encrypted algorithm negotiationAllow SMIME SoftCertsEnforce Device encryption