Once you've overcome the current limitations of HTML by adding native code, offline mode, hardware support, local file access, and so on, is it really meaningful to call the result a "web" app? It's more like a native app written to a cross-platform layer (huh, somebody told me those were evil) that you can easily install from a web page.
The names "web" app and "native" are far too coarse grained to be meaningful. The important parts are the details.
Zero install or heavy weight install? Cross platform or single platform? Offline accessible or not? Safe for anyone to use, or not? Deep linkable or not? Etc.
These attributes can be mixed and matched. And will be.
