First of all - I really like the merge of MU into 3.0 and the many other improvements in 3.0.
That being said there is one thing that seems to be very odd to me since we are now dealing with a multi-site environment in a 'network' rather than a multi-blog environment.
In the old terminology, you were running multiple blogs with one main blog so a single point (on the main blog) for registration and login wasn't a problem (as it's more or less a community).
Today, with 3.0, we call it a network of sites in which can hold completely different no related websites to each other. In this situation it's weird that you will be redirected to the main site for registration and login...
It would be great if the following would be possible:
- register on the site you want to register,
- logon on the site you currently are without seeing the main site,
- and if you happen to register on a different site in the network with the same email address (with the same or a different username) you should be able to register without getting a the notification that the email address is already in use... (the system should thus allow multiple usernames per unique email address and log which username is used on which site).
My thoughts are in the direction of a network where you have a personal blog as the main site, you have a niche blog, and also host some (small business) sites for family / friends / organizations in the same environment.