Different game.
Different developer.
Different goals.
There. Confirmed!
Calmy dive into your Argonian character and don't give a f--- about what's happening with TESO.
Bethesda Game Studios is responsible for 4 consecutive mainstream hits, that have all won multiple GOTY awards. That team is not going to just be sent home to not make games anymore.
On a single player level, TES games are a huge hit, and Bethesda is not going to stop that just because a sister studio is making an MMO. Todd Howard and his team are going nowhere, and they will still continue making single player games going forward, I can guarantee it.
Only source we have is Pete Hines Twitter: https://twitter.com/#!/DCDeacon/status/198430022162317312
Which actually does not necessarily mean they are creating a new Elder Scrolls game. Could be something else, like Fallout 3 was.
That's it , all I ever wanted , have fun with your TESO , my adventure shall continue !