Ask HN: Is it worth learning Win32 API anymore?

I've been teaching myself c++ recently and feel I have reached an intermediate level in terms of understanding and using the language.

I am in the process of learning to build desktop applications and have been trying to learn it from the ground up using the win32 api and have spent many recent weekends using winsock to build chat applications etc. I tend to use codeblocks for development and hence don't have access to MFC which I've heard 'makes things easier'.

I am interested in moving into mobile development (particularly software that sits close to the hardware) eventually but not sure if I should continue to hammer away at learning application development basics through Win32 API to gain a solid grounding or just jump into mobile development?

What would be the best place to start with learning mobile dev? Android, windows, symbian or iphone?