I posted these on the first photo, but I'd rather them be in the context of an actual post, so I'm reposting them here:
Scott Bourne (who I rarely agree with) brought up some interesting issues with licensing photographs (or anything uploaded to G+, technically) last week: http://photofocus.com/2011/07/06/google-plus-read-the-fine-print-before-you-sign-up/
Note: You definitely can retain your copyrights, but you're giving Google a free irrevocable license to use your content and give it to its partners for use commercially.
I agree that the ease of doing it is nice and gives a pretty good user experience for the readers, but are you saying you're okay with the licensing side of publishing via Google+?
EDIT: Formatting fix.