The capacity planning model for OpsMgr07 has now been released for SCCP 2007. You can download from here http://www.microsoft.com/downloads/details.aspx?FamilyID=6fec1f12-a62c-4e8d-8a19-56879192adc3&displaylang=en
The SCCP model download catalog on http://technet.microsoft.com/en-us/sccp/bb969059.aspx will be updated to reflect the release shortly.
Running the MSI on the download page above will install the model on a computer with SCCP 2007 already installed. If you need Capacity Planner 2007. Install it first from here http://www.microsoft.com/downloads/details.aspx?FamilyId=E754F35D-59DB-4BC4-8386-E83E66A16FAD&displaylang=en