If you find yourself blocked by a required prerequisite when you're running setup to evaluate Configuration Manager 2007 Beta 2 in your lab environment (or TAP production environment) there is a setup switch than can come to your rescue: Setup /NoPrereq. Using this setup switch will cause setup to run and skip the prerequisite checking process. This means that none of the prerequisite check rules will run during setup so I'd recommend that you first run setup with the prerequisite checking turned on to ensure that you've resolved as many setup prerequisites as you easily can.
This setup switch will only be available in pre-RTM builds. So when Configuration Manager 2007 is officially released, this switch won't work. For now though, if you're installing any of the currently released builds of Configuration Manager, this switch will allow you to install a Configuration Manager 2007 site without verifying installation prerequisites.
Hope this helps,
~Jeff