SBS 2011 Migration from SBS 2003

Existing client has infrastructure including SBS 2003, multiple workstations, third party apps running on Server 2008 Std, as well as various network resources.  Infrastructure also has other businesses connected to the same subnet due to incorrect network management.  The concept for the project is to segregate the other businesses into their own IP subnets and away from the client's server network.  This project was broken up into 2 distinct phases.

Phase1:
By using separate physical switches we connected all workstations that were a part of the server's network to a new gigabit switch.  We kept all connections coming from the other businesses connected to the existing 10/100 switch.  Then a new "optional" port was configured on the Watchguard firewall to host the new server network.  The 10/100 switch was uplinked to one of the 2 new gigabit switches in the rack and then that gigabit switch was plugged back into the trusted LAN port on the Watchgaurd firewall.  The new server hardware was plugged into the remaining gigabit switch and the switch connected to the optional port on the firewall configured as the new private LAN connection.  Doing this allowed us to separate the two networks but maintain internet connectivity for the other businesses.  We then changed the IP scheme for the private network to a more Small Business Server compatible one.  This would allow for the SBS installation to recognize the necessary network components (DHCP, gateway, etc...).  I configured the firewall to allow full communication between the two subnets.  This would allow us to migrate all the computers over to the new server's domain without running new runs.

Phase2:
After installing the SBS11 as a normal installation, I configured it with new user accounts for the existing users including mailboxes.  When I performed the migration we moved each workstation that was in the same physical area of the server to the new gigabit switch dedicated to the new subnet and domain.  We performed full backups of the email and other settings using the export feature of Outlook and Windows Easy Transfer.  We then joined the computers to the new domain using the SBS11 http://connect site.  We then setup the existing users with their new accounts and restored all their data and email using the backed up files.  I configured all traffic that was going to the old server through the Watchguard firewall to point to the new server (email, web, OWA, etc...).