|via @andyi on flickr|
Take for instance this link:
If you hone your skills in developing browser based solutions that are awesome on smartphones, then you are gaining long term valuable skills, as you can expect that pretty much all phones for the next 5 years will have browsers on them. Learning objective C or the android API is a higher risk investment of your time - who knows what phone will be hot next year?
If you need to access lower level hardware, like the accelerometer or the camera then you probably need some closer to the metal code. Then again, location aware browsers show me that these sorts of interfaces will be exposed more and more through the browser as time goes on. Maybe you are doing graphically intense 3D visualizations, then that needs hard core C, but again 3D optimized graphics libs for browsers are on their way. Finally, smartphone browser apps don't get you into the app store, which might or might not be a good thing (no approval process but no chance to hit the app store lottery and make money).