The bigger Problem in Mobile Applications is the Platforms. There are multiple Platforms that you must develop your mobile application for and they are always changing, which will be eradicated by using PhoneGap as its a single code base. For an example if we had to develop an app in native for all the known technologies which are iOS, Android, Windows and Blackberry, it will make an impact for both time and effort. But where as in PhoneGap it can be much more simpler as its coded once for all the above mentioned platforms with less time. So thats 4x faster development in the same time.