TechTool Pro 7.0.1 will display a warning dialogue that it has not been tested with OS X 10.9 (Mavericks). The warning is there as a safety mechanism in case the final release of OS X 10.9 (Mavericks) included any last minute changes. You won't be able to create a new eDrive or repair permissions until the update is released for the same reason, but all the other tests and tools can be used safely in the meantime.

TechTool Pro 7.0.2 and later has removed this dialogue and is fully compatible with OS X 10.9 (Mavericks).