I'm a tournament Scrabble player and I want to do this for Scrabble. The only choices we have are a very buggy and crappy phone app, made by EA (missing tons of words) that only allows correspondence play, and a client written in something like Java 5 and hosted on some computer in Romania (http://www.isc.ro) to avoid the copyright issue. The latter recently crashed and wiped out about a year of data because presumably the maintainer did not do backups. I can't even use it because I'd have to downgrade Java on my computer.
There are great open source tools out there for analyzing/simulating games that can be hooked up to the proposed site (http://quackle.org for example). Both of the aforementioned programs (the EA one, and ISC) have very elementary analysis with nothing close to look-ahead.
I've written a study server at aerolith.org using HTML5/new technologies and am going to add multiplayer soon with Websockets. My time is very limited due to my job, but I'd be willing to help with an effort to recreate something like this amazing site for Scrabble. But again the main issue is the copyright/trademark issue, and the fact that EA has the rights to online Scrabble in North America. If anyone has any ideas it would be awesome.