mostly unrelated but: could the parenthetical after the title of a post be modified to include subdomains? Seeing (google.com) made me think Google was saying "No matter what price we choose...", whereas if it said (plus.google.com) I'd realize it's likely just a "blog" post by somebody.
edit: or is there a good reason we shouldn't do this?
I upvoted you because I do agree it is a bit confusing. That being said, whenever it is something official from Google it tends to be on one of their blogs (Blogspot) (e.g. googlecode.blogspot.com, googleblog.blogspot.com, etc.). For blogs, HN captures the subdomain since the blog's name is captured within it. In the case of Google Plus, knowing that it is Google Plus (plus.google.com), we would still be hard pressed to know which user/person is posting.
God forbid, Google starts posting their product news/updates on Google Plus. Then, I would heartily agree with your solution.
edit: or is there a good reason we shouldn't do this?