the e7 is running on the symbian^3 os. Anna, belle, cindy, etc, these are just the names used to identify the updates, its still a symbian^3 device, like n8, e6, x7, c7, etc.
All symbian^3 handsets get the free firmware updates. Its easy to do, theres an app in the phones and it alerts u when the updates are available and u just update using the app.
Release dates depends on ur country and service provide, for example, anna was released months ago but many countries are still waiting.
New batches of phones have the updates already, but even if ur phone doesnt, it will be available free once released.