Meanwhile, the beta test has ended and the cloud feature was released as full version, being part of Deep Fritz 13. As far as I can tell, it works fine except for minor "cosmetic" details regarding the expected nps and Let's Check speed index, in the cloud screen. I do not doubt that an update/bugfix will appear sooner or later.
Also, rating list results indicate a small but measurable strength improvement of the (Deep) Fritz 13 engine compared to the singlecore version, in addition to the mp feature, IOW in singlethread comparisons. At IPON, that's +17 Elo.