On SBS SP1 Fulfillment
There has been an issue for a while with getting the SBS SP1 installation media from Microsoft for those who have SBS 2003 Premium and wanted to get ISA 2004 as part of the SP1 package. The issue is being worked on, but there is no ETA for a solution at this point. People who are not yet running SBS 2003 SP1 should definitely download and install the non-ISA updates, but those who are wanting to get the ISA 2004 update for their Premium install will have to wait a bit longer.
The Official SBS Blog has a post about this issue and will be the official communications channel when the solution is ready.