Heard from Fein;
"It is true that Bosch have recently launched a version of an oscillating machine. The machine is designed for DIY applications and has limited power and very few accessories. The blades for the Bosch machine will fit the old style MultiMaster (MSxe) but will not fit the new style MultiMaster (FMM 250Q).
We have not entered into any kind of agreement on the manufacture of blades or accessories with Bosch, they have simply taken advantage of lapsed patents."
So now we know :-)