A workaround: Well, somewhat. You can use the 32bit xDBC driver with Microsoft Office 2010 32Bit version on W7 64bit platform.
I've deinstalled the 64bit version of the MS office suite and reinstalled the 32bit office suite on my W7 64bit machine. I can now use the 32bit Filemaker ODBC driver from 32bit Excel and Access.
This should buy us some time untill a Ms certified 64bit Filemaker xDBC driver.