In a semi-related conversation with Shoemoney's Jeremy Schoemaker, he tells WebProNews that he just talked to a Google engineer, who "alluded to the fact that Google might be developing a system with Google+ to allow people to comment."
Given that our conversation (more on this in a coming article) was related to blog comments, this leads me to believe we're talking about Google working on a project that would allow blog readers to comment on posts using their Google+ accounts.
This wouldn't exactly be a surprising move, but this is the first we're hearing about it.
Facebook and Twitter have similar tools. Facebook's is even very integrated with the Facebook.com experience. More on that here. It's hard to say if Google would have this kind of back and forth (from stream to blog post) integration, but if I had to guess I would say that it probably would, given Google's "Google+ as your identity" philosophy.
We've reached out to Google for more info. I'm expecting the "we have nothing to announce right now" response, but we'll see what we get, and update accordingly.
Who you are is clearly important to Google - including in search results. If Google launches a tool like this, people just might have more incentive to use Google+ as their commenting voice (assuming they're leaving quality, insightful comments) than other options. I'm willing to bet it will be a super popular choice for the blogs themselves to utilize.
It could only help in the expansion of the Google+ brand itself as well.