More complete discussion here: http://graphicdesign.stackexchange.co...
The file format dropdown in the new 'Extract Assets' feature works only occasionally and (apparently) randomly, generally being stuck on the default png-32 setting. Would love to be able to produce SVGs with this feature! I'm running a fully updated version of CC 2014 (as of 10/10) and Mavericks OS. Otherwise its an awesome feature.