I was thinking to create somesort like blogspot.
a blog for all with a subdomain.
i found Wordpress MU, but after some research i found that, there's no theme edit for user. so thats mean they going to use the normal theme right.

is there any other Multi user blog ?

BlogHoster.net is the solution for you. they provide blog hosting software and this is the best i ever seen.

wow bloghoster cost too much $$$

it is worth the price :) trust me!

any other recommendation?

Moved to Web Design and Content.