After a lot of mistakes i have done while modifying jsb2 file the first think i thought was XML version of project file.
I think it could give us following advantages:

1. Validating for well-formed project file(at design-time and at run-time as well)
2. Ability to disable(to comment) any unused blocks in xml against the removing one in json

So i going to implement xml support feature in JSBuild2.
Any comments are welcome!