A few things to consider:
If the weather did in fact play a part in the Air Asia crash, it would be interesting to see if the data transmission would have maintained its reliability throughout, the same could be asked of AF447. Very good satellite reception often collapses during large thunderstorms so I would imagine the same to be true for transmission, perhaps this could be improved.
The legal implications of sending CVR data across satellite communications could be tricky as this data is specifically not stored off site for the benefit of pilots. Should the data be stored off site there is no guarantee that the data would not be used against the tech crew.
There is certainly a case though to, if nothing else, transit a better "last know location" signal to assist in recovery efforts to avoid these massive delays (e.g. AF447 and MH370)