Earlier, with a SQL Azure subscription, we were allowed to provision a single server only. But now with May 2011 SQL Azure release, we now have the facility to have multiple servers under a single subscription.
couple of months back, i had this need to check SQL Azure performance for data that i stored in different data centers. But back then, i was allowed to provision a single server with a subscription. So i had got myself multiple subscription so that i could create SQL Azure servers in different data centers. But fortunately now I will not have to manage multiple subscription just to provision databases in different data centers.
I have written an article on beyondrelational.com about the step by step guide to provision multiple servers under a single subscription from the New Azure management portal. Click me to read the artcile.