No, ItsNat is not a silver bullet, it has a focus in some problems and just solves some problems.
Disclaimer: I'm the author of this tool.
Cool... I have watched your slides "How to choose a web framework and be surprised" (nice way to explain the differences between ItsNat and other frameworks... use existing stuff many people know and compare it to your work), have liked what I saw and it seems that ItsNat aggregates many features from other frameworks. As HN is a cool community full of experienced Java programmers, I wanted to ask for their opinion. The question still stands. :)