I know the adv and disadvantages of both.
I just need some recent stats which show the market's adoption or opinion.
I tried three ways to develop mobile applications.
First method is to use frameworks that will take your html/css/js files and package them into mobile applications depending on your targets (BlackBerry, iPhone, Android, ...). I used PhoneGap (known today as Cordova). I didn't like it at all because the UI's rendering is so ugly on some devices and the user experience is broken. I had to use it with jQuery Mobile because it gave me a good UI design start. I tried some Phonegap Android generated applications on my personal device and it's really horrible. Some of them got rejected by Apple because of that ...
Second method is to use
Personally, I put in place apps that can: Take a photo with the device then send it to a remote server, send messages to twitter/facebook, advanced geolocation, etc.
Third method: Native! It would take time if you target both iPhone and Android but, the big advantage is that you can create anything you want without being tied to a Framework for areas such as games, augmented reality , etc.
In my opinion, if you want to create simple applications with some nice features (weather, twitter feeds, sending on a facebook wall, ...), use Appcelerator Titanium SDK. It converts your code into NATIVE.
If you have time to spend learning native languages, do it. It's the best way ;)
Hope it helps.