If we are allowing our members to register or link their Facebook and Twitter accounts in the forums, it might be able to allow those options for blog comments also.

For example how they do it on a lot of news sites (cnn, fox...).

Good idea and not only on IP.Blog

Comments are a global extension and not limited to Blog. I'll move this to the IPB feedback forum so it can be considered.

I would also like to contribute to this based on a post i made earlier: Modify Guest Sign In.

When a "Guest" elects to use the "sign in" option, after they eventually sign in, the system does not return them to the blog post. Even you use the "go back" button on your browser, once you are back on the blog post, the page is not refreshed. As a result, you do not know that you are signed in. This is counter-intuitive and needs correcting.