Username or EmailPassword
v4 has summary (important part at this stage) written in smaller font than unimportant information.
I have to correct myself: summary font (and some other) does scale along with browser default font size, submitter and comments count font size is constant. Because I use Opera with reduced default font size (16>14), for me summary is written in smaller font; actually it is probably just font sizing problem in css.
Of sourse this doesn't void ideas behind my previous comment (and doesn't make summary more readable).