Yep. I've spent some time investigating the possibility of using web views to replace some native Android/iPhone views (e.g. ListViews), and I assure you it's not easy. We didn't do anywhere near as much stuff as Facebook did (of I read that right, they bundle a version of WebKit with their app, and write client side compilers from JavaScript to native languages for phones with bad or no JavaScript environments). It's getting there, but web still hasn't quite arrived as the write once run everywhere platform. At least it's somewhat reassuring that Facebook still has lots of problems after spending many more hours on the mobile web than I have.