what are the little white 'things' next to each persons name?
It took me a while to figure out what you're talking about.
There are message icons, not next to usernames, but next to the topic titles in posts and also in the board listings. The white things are pages, and if a poster doesn't select a message icon when s/he creates a post, that's the default. (I changed the message icon in this post to a smiley, so please tell me if that isn't the location of the 'things' you're seeing.) There've always been icons in those places; this one just looks a little different than the previous standard message icon. Knowing MB, any number of the updated icons could change to ones he likes better.
What I'm wondering is what is YAU?