After more than a year in private beta, the new Web 2.0 style MyYahoo is being rolled out today to all MyYahoo users, the company says. MyYahoo is the biggest player of all web start pages and any changes made there will effect millions of mainstream users.

The best is yet to come, though, as Yahoo! also said today that MyYahoo would open up to outside developer applications in the next few months. That's among the changes we've been waiting for since the company's big announcement in April about a shift towards whole scale personalization and data portability.

We reviewed most of the changes being made to MyYahoo when the private beta launched in March 2007. Then, one year ago last July, Josh Catone here at RWW called for the creation of a MyYahoo platform as one of the best hopes Yahoo! had for its future.

MyYahoo's market share in the startpage field is massive, Comscore estimated in January that the site sees nearly 50 million unique visitors each month. Google's iGoogle startpage is a distant second with just over 20 million. Facebook, however, is destroying both services - it's at an estimated 80 million active users worldwide and growing fast.

The Facebook platform hasn't shaped up as well as was hoped, however. While Facebook's platform faces growing problems with privacy, decreased developer interest and lower than expected user engagement - a MyYahoo platform would be hot. The placement of Facebook apps on the public facing profile pages instead of the user facing admin pages is a problem that MyYahoo wouldn't suffer from. Additionally, while Facebook users arguably use the service for communication more than for the other type of activities that so many Facebook apps facilitate - MyYahoo is already a full-service, multi-use portal for millions of people.

If the Facebook platform was a first run for the social networking app platform paradigm, and the LinkedIn platform is the most sought after place for developers seeking a professional userbase, then a MyYahoo! platform would be the sweet spot for mass audiences of mainstream users.

We hope that the general availability of the new MyYahoo will be one of the last key steps before the platform opens up. In response to our inquiry about the time frame for the platform, Yahoo! sent the following response:

"This strategy involves opening up Yahoo! in three phases throughout this year (2008) and next: the first is to open up internally, and you will see products like Yahoo! Search, My Yahoo!, and Yahoo! Mail open up and become more integrated, sharing content and data. The second phase is to open up the Yahoo! platform to third party developers, which will be happening throughout this year, starting already with SearchMonkey. The third phase will be to allow the Yahoo! experience to be accessed off the Yahoo! network and you can expect progress on that phase throughout this year and into 2009."