As a long time C4D user i'm fairly certain that for SL rigging its useless as it's native collada (1.41) exporter doesnt export the kind of weight/vertex map SL wants............the weight info is there but from what i understand the weights are stored in the actual bones and not the skin when using the C4D collada export.
Personally I would love to see a SL rigging/animation plugin or script suite for C4D...not gonna hold my breath though:)
before anything I would like to see the material shuffling with custom LODs made in C4D fixed because im currently having to break anything that needs multiple faces/mats into pieces,,,,,.
Lazy.