ESLint is pretty awesome - the project has a great team and always adding new functionality (cache and then parallel linting sound great)!
Although it isn't unique for all the features listed, as JSCS has the same things: an autoconfigure feature, built-in (as well as user created) presets/configs, multiple formatters, custom plugins/rules, custom parsers (esprima/espree/babel), autofixing of almost all rules. Hopefully both projects can benefit or integrate better together more in the future? (I contribute to both!)
I think autofixing for all rules (maybe with https://github.com/cst/cst) would be a nice goal for the future when thinking about the next-generation of linters. Making it easier to update configs when new rules/options are added would be nice as well.
There's an issue for a CST (AST with whitespace, comments, etc) in the estree repo [1]. JSCS is planning on using https://github.com/mdevils/cst for future autofixing rules.
The beauty of this pretty-printing solution (merging it with the parser) is that you don't even need any parsing tree to be constructed. The parser will simply walk the stream and annotate it with the pretty-printing instructions (pushing an popping the indentation context, adding the weighted break candidates, etc.).
