Looks like the good folks in Redmond got some time to write up a much-needed troubleshooting guide for TFS server installations.  You can find the guide on MSDN using the following link:

Troubleshooting installation of Team Foundation

The guide goes over how to interpret the installer log files, as well as diagnosis for many common TFS errors.  Here's a list:

1. Error 32000. The Commandline ‘[1]’ returned non-zero value: [2]
2. Error 29112. Team Foundation Report Server Configuration: Either SQL Reporting Services is not properly configured, or the Reporting Services Web site could not be reached. Use the Reporting Services Configuration tool to confirm that SQL Reporting Services is configured properly and that the Reporting Service Web site can be reached, and then run the installation again. For more information, see the Team Foundation Installation Guide.
3. Error 29109. Team Foundation Report Server Configuration: SQL Reporting Services configuration encountered an unknown error. Verify that you have sufficient permissions to configure SQL Reporting Services, and try again.
4. Error 28806. An unexpected error occurred. Verify that SQL Server Reporting Services is installed and running on the Team Foundation app tier and that you have sufficient privileges to access it. For more information, see the setup log.
5. Error 29000. An unexpected error occurred. Verify that SQL Server Reporting Services is installed and running on the Team Foundation app tier and that you have sufficient privileges to access it. For more information, see the setup log.
6. Error 28805. The setup program cannot complete the request to the server that is running SQL Server Reporting Services. Verify that SQL Server Reporting Services is installed and running on the Team Foundation app tier and that you have sufficient permissions to access it. For more information, see the setup log.
7. There is an error with the collation settings for SQL Server. The collation settings are not compatible with Team Foundation Server.

There are also sections for troubleshooting the installation of Team Build or Team Explorer in Visual Studio, as well as some helpful hints for post-installation pains.  This article has now taken the place of a dozen of my favorites -- thanks Microsoft!