From a motivation point of view , it's important to keep a mix of new features in with the bugfixes and user experience improvements. Features are new and exciting, not only for players but for myself as well. Focusing just on bugs and tweaks is a sure-fire way to kill any motivation. To that end 1.3 will contain a healthy mix of both.
After 1.4 Masklings will be getting a lot more interesting to interact with. Trade and diplomacy are both on the list, possibly even subjugating Maskling tribes as vassals.