Don't wanna sound like im agianst the idea but i don't think many what to prolong the game any longer.
The initial beta release will not contain all features. It will only be a base with the bare minimum of features. Over time we will release game updates which will introduce new features.
Take WoW for an example. There it's called Patches: Updates that give changes to the gameplay, and some times new features, more quests, etc...
Just saying...