MacWorld UK posts about a possible secret announcement at Quicktime Live (Feb 11-13).
This year's sessions include "a super-secret workshop" to be announced at the event, as well as an Apple keynote to kick-start the event.
Previous info re Quicktime 6 and MPEG-4 can be found in this previous macrumors article
Correction: The above link was originally attributed to the wrong source. The article can be found at MacWorld UK