Where is Azure's previous portal?
Few days ago the new portal was upgraded. The service bus was maid available (and few other new features) but the CTP announcements and the link to the previous portal was removed.
Unfortunately as for today not all Azure features are available in the new portal, so the previous portal is still required. For example to use ACS or Data Sync we have to use the previous portal.
Then a new menu will be opened, and a nice menu item will point you to the previous portal.