I just ran a test on the the new G+ photo editing thingy. It isn't bad. It is in fact a simplified version of Picnik but is still potentially useful. This was a photo that I posted a couple of weeks back via G+ and it was very easy to open it, edit it, save a new copy and post it back into the stream.
The downside is that they have simplified some filters and dropped a couple of the really useful ones like focal blur. If they could reintroduce those this would be really useful.
For basic fixes it is good though. Noise reduction is the only 'basic' that is missing.