Wiimote recording seems much, much, much more consistent after some recent fixes. It seems that with no save states, it syncs perfectly, and even with save states it now syncs most of the time.
Anyone who's interested, test it out, and let me know how it syncs, including when playing back with read only from a save state. Builds are at
http://dolphin-emu.org/download/list/wiimote-save-fixes/1/
By the way, tasing with this now, my experience has been that when playing back a movie with read only from a save state, it'll either desync right away, or sync perfectly, so even if you still get desyncs (i am still getting a fair bit, but still much less than before), it may not be necessary to play back from the start to find them, and just have a save state before a section that you know is prone to desyncs, and is confirmed to sync from the start, then if it syncs through there, it'll probably sync the rest of the way. And if it doesn't, then it'll probably also desync when played back from the start.
Obviously you should still check sync from the start often, but this can get less and less practical as a movie gets longer, so it's good to be able to check sync from a save state.