Right now, if someone has more than one blog, the situation seems to be as follows:
among the existing blogs the one that was first created is the "primary" blog, meaning this is the one which all the links in the blog bar at the top of the page lead to.
To the people at Automattic: could you please add an option in some kind of "overview" or "preferences" menu that lets us chose which of our blogs is the primary blog?
I don't know how much effort that would be - all I can say is that this is on more factor of the blog administration that rather annoys me.
I am sorry if this is not writte in a very friendly tone, but I am already so, ... well, "angry" is probably the right word - about your blog deletion policy that I am not entirely unbiased rigt now.
Long post about this topic from me here:
http://wordpress.com/forums/topic.php?id=2958&replies=4