Given enough time, yes, any developer can learn another language, but you're missing my point. A C developer can't just stand up, walk over to a Mac and sit down and start writing an iPhone App. There's a huge learning curve. Likewise, an Apple Developer can't just walk over to a PC and start developing on .Net.
I'm a web developer and I hang out with a ton of government C & Java developers that work on our military base. I've even tried to get them to help me out with an iPhone app before. They can't do it. The initial learning curve is too steep to do it on the side.
HTML 5 will become a way of life in the next 2 years
I like HTML5. I use it daily and love the things that it can do. I've written many web apps that use it. With that in mind, I can guarantee you that HTML5 will not have a significantly larger market share over native apps in 2 years than it does now. Native is still the way to go.
- HTML5 wasn't helped when Zuckerburg called it the worst mistake that he's made (trying to create web-based vs. native).
- The discoverability, performance, and general need for connectivity of HTML5 apps is another huge problem.
- Some mobile web browsers still don't support all of the attributes of HTML5.
- Design and speed Issues with mobile vs. desktop HTML5.
- Gaming is sub-par.
Hell, I wish HTML5 WOULD become the standard. It would make it a lot easier on me. I just can't see it yet.