Hey there,
Firstly, my goal is to develop mobile (Android and maybe iOS) applications.

Secondly, I've been coding in AS3 for about 4 years (well ever since it came out. I think it was 4 years) and I only know how to code in AS3.

I know that Java is a more powerful language but Flash(AS3) can export my projects to Android and iOS via. Adobe AIR, while with Java I would have to learn Objective C to create my project for iOS.
There's also the option of going with C# (it's a relatively new language and I like that) as with the upcoming Delta Engine it will easily be able to export my projects to Android and iOS by only writing C# code.

So in a nutshell: For an Android developer... Stick with AS3, Java or C#?