Existing iOS phones will probably not support WebGL, and PhoneGap only supports one sound at a time. This is simply unacceptable and is not likely to change.
Yes, the AppMobi system (which is based on PhoneGap) requires the iOS/Android SDK. But have you read the directions? Both of the SDKs are free, and the system builds directly from a set of HTML and JS files, just like PhoneGap. It's basically drag-and-drop, after the code part is exported properly (as it would be from a Construct exporter).
This would give us working apps now without having to wait for WebGL and sound support which will probably never come. The steps to turn it into an iOS app are literally drag-and-drop if the code is correct.