There are several file types that cannot be directly imported into CT (such as word/excel macro files). Or, you may sometimes need to translate PowerPoint slides only.
Then, you can use Wordfast Pro 3 (demo version; free) as an additional file filter for CT (for the time being; until (hopefully) these features are implemented in CT)
WFP demo version has a cap on the size of resources (TMs and glossaries) that can be imported, but it can import a source document of any size.
1. Import the source document into WFP and save it.
2. Open the WFP work file (.txml) in CT and translate it.
3. Open the WFP work file in WFP and choose "Save Translated File."
Yes, those file formats that are not directly supported by CT.