This has been discussed many times here but dynamics keeps changes every month. Now we have Amazon Fire coming up as a new platform. I agree Web apps are "little" slower than Native one but sometimes they makes sense if you have a web service.
• Apple recently passed on the benefit of new Nitro JavaScript engine to UIWebView, WebClips
• Windows 8 is promoting HTML5
• Leaked official iPad Facebook is kind off hybrid between native & web
• Linkedin recently launched HTML5 + Node.js app
• Using platforms like Titanium or PhoneGap is also not recommended for serious apps
Where is this heading? More of Web apps in future?
There are pros & cons, the idea here is to discuss what makes sense today.
However, web apps were tried before - the original iPhone, for example - and were overwhelmingly underused and rejected by users. Has that changed? Possibly, but until we see the next crop of webapps we may not know. Personally, I feel that there is a certain irrational preference for having an app installed on your device, where it won't change or update automatically and will be accessible offline (even if you can't do anything useful with it).
Having said that, web apps have expanded and done quite well in the PC world - the idea of a native Facebook desktop client is laughable, and I'd guess that most average users use a web app for email.
It'll be interesting to see how this battle goes.