When upgrading from SCCM 2007 to SCCM 2007 SP1 be aware that you will have to download and install two patches that are available only through MS support. These patches are:
SCCM 2007 R2 version is out. You can download free trial from MS downloads site.?
Note: Since this is trial version, it can only be installed onto SCCM 2007 trial version. You can not install this trial version over registered product. Full version will be available to MSDN subscribers or other MS distribution channels.