According to this article over at Massively, Elder Scrolls Online is aiming for monthly content updates. Not only that, but they intend for these content updates to be rather large and contain more than just a “funny hat”. Of course, this is a very, very good thing. How long can they stick to that promise though?
I think the first month or so after release will consist of mainly bug patching and systems improvements. Its really hard to get out large content patches in the first month. Bugs that they did not find during the beta and during stress tests will rear their ugly head. These will take priority. After that is when you will start seeing some content patches. What they will entail and how big, is any bodies guess at this point. But, they will have to be pretty large to justify the $15 a month. Gone are days when people will pay a monthly sub fee for only the privilege of server access. The only MMO that can do that now is WoW. ESO will need to be much more aggressive.