1. A bookmarklet. When I'm on a page and want to shoot a link over to people following me on Twitter, or Facebook, all I have to do is click a bookmarklet and type a comment and hit Submit. The process is considerably more onerous for GP. Lots of things to remember how to do. I don't remember. So I don't do.
2. A very very simple API. Just give me a way to post an item to Google-Plus from a web app. I already have such an app for Twitter, so I can use my own tools to write and publish where ever I want (including to an archive so I don't lose these suckers). I have the problem solved on my end, after years of fussing and figuring. Now please, the API only has to do this. You have to be able to write one of these in an afternoon.
3. If you really want to blow people away -- I mean really blow them away with a very powerful idea about data independence, publish an archive, in XML or JSON (RSS would be nice) to my S3 bucket, of everything I write on Google-Plus. Then it would become the home network for every power user of social networks. And tool makers. It's not enough to make the data easily exportable. If you really want gobs of (deserved) attention and kudos, and to raise the bar really high for your competitors, provide a real-time off-site backup, and at the same time connect up to Amazon's cloud. You may not like them, but we do. Lots of us. Worth reaching out to.
PS: To Bradley Horowitz who, in a comment here, said I know how to reach him. I do. I write a blog post on Scripting News. (I didn't want any of my readers to think there was an insider's back-channel. Nope. Not here.)