To be succinct and to answer your question directly, I think it is very easy. The only trouble is when debugging, but that should hopefully be resolved by the time the SDK is matured and released.
I was able to create an app in less than 15 hours, which includes learning the framework for the first time (a few hours spent reading the Oreilly book). Actually, my profession involves R&D prototyping using various technologies. Specifically, part of my job entails learning new frameworks/languages/etc while developing a prototype, in order to produce a report of whether that technology can/should be used in my enterprise and the efforts/resources required. Palm pre development is on par with development using any framework I have come across. No worse, no better given an even playing field.
However, if you are already fluent in object-oriented programming in javascript, and the MVC pattern, and popular
JS frameworks (prototype, dojo, etc), your experience will be more efficient and productive than others.