We have added a new feature to the g3 message page. Now whenever someone you are watching posts a blog, you will receive a notification on your message page, just like when they post a new gallery item.
For those interested in the technical details, this has been implemented a bit differently in the back-end than the other notifications. Since this relied on detecting actions that take place inside phpbb3, instead of inside the gallery, I opted to try and not modify the phpbb3 source code at all. So instead of creating the messages in code after a blog was made, I added a trigger to the blog table, so the database automatically populates the messages when a new blog is inserted. This model seems more elegant, and I will use this going forward.