OneApp is reportedly to be able to run on any feature phones with Java (most likely J2ME CLDC+MIDP). So here come the questions:
1. Why bother with OneApp? Just go ahead downloading those Java apps from the Internet...
Today, even complex software like Opera Mini provides Java client for many feature phones, as long as the phone has J2ME. However, keep in mind that OneApp introduces a middle-man between your device and the software service provider (Twitter, Facebook) that, very likely, acts as a proxy or an agent to process transmitted and received data. This is the same idea as UCWeb Java version. It seems optimization enabled by the cloud is the key benefit of OneApp.
2. How difficult is it to develop an app (or widget?) for OneApp such that it runs on most cell phones in the world?
3. Is it only available from the operators? No free download?
It seems to me that OneApp folks are seeking collaboration with phone OEMs and operators to ship the product. No indication of free download yet at this moment. Well, to make this massively popular, it has to be made available for download from a Java midlet manager or some sort. To feature phone end-users, this should be like an one-stop shopping for several cool Java apps in a single JAR/JAD. If this is true, naturally the next question is, without charging license fee from OEMs and operator, how can Microsoft make money from this product? The underlying platform is NOT Windows Mobile, so boosting WM market share is not the goal here.