Just tried this out on one of my sites. A google authorship page was added 5 days ago. The SERPS are already showing my site with the Authorship photo for 90% of my pages which is really quick.
Any increase in position: No
Any increase in CTR: No
Was it a total waste of my time as I'm now going to get enquiries, spam and silly questions and hate posts against me through yet another social profile I have to watch, maintain and keep a close eye on: Probably but too early to tell so I'm going to give it a bit longer.
(FYI - I have established a reputation on + and started building followers and participating in the community. There are much better social networks out there that actually deliver traffic via an active social profile but G+ does not seem to be one of them.)