Well, it's not much of an update, really, but word on the street (via io9) is that SJA will be serving as a 'launchpad' for the new Doctor Who animated series
Dreamland, according to the series' head writer, Phil Ford.
Apparently there's some events in the first story of SJA Series 3 that will have a direct link to
Dreamland - so it will not be broadcast until later October (after October 16th). I have no idea how this might affect the airdate for
WoM, but apparently there's six separate short parts to
Dreamland that would be available via the BBC's red button initially, but would be combined for an actual separate broadcast at a later date. Link with some spoilers for SJA here:
http://io9.com/5369008/sarah-jane-spin+off-launches-doctor-whos-animated-adventure