Is it possible to let the user update from the non-market version of an app to the market version?

I have developed an Android app which is currently in an open beta phase, which means that each interested user can download the apk from the project's website (http://www.goodnews-mobile.com). I have already provided some updates through the web site and the users had the possibility to gracefully update their current installation without loosing any of the app's data. Now I want to release a new version of this app in the Android Market.

Here is the question: Will the users, who installed the app from the homepage be able to install the new version from the market without needing to uninst开发者_如何学编程all the old version?

From a technical point of view I have ensured everything necessary to provide a graceful update (e.g. using a private key for signature that matches the market rules, maintaining version name and code in the manifest, etc.).

If you use the same key for signing your apk then your users will be able to update via Market. Just make sure it's not the test keys you're using (by default Eclipse uses the default test keys to sign apks before install them in an emulator).

Once you start using a developer key you can't use any other key to sign the same application (identified by the application's top-level Java package e.g. com.example.myapp).