GameProducer.net is reporting that there is new rating system available, rated without cost and by developers. It is called TIGRS

TIGRS is simple, three age ratings (Family Friendly, Teen Content, Adult Content) and many rating descriptors. TIGRS ratings are created with rating generator.

Will developers and more importantly the retailers adopt this system?

I guess it's a good idea for indie games -- that's what it was created for -- but I doubt if it will be used by commercial enterprises. Paying money for a game rating is a status symbol too.

Apart of that, I like it.

It's excellent for indie, but it won't be adopted commercially. ESRB is too ingrained into everything.