Press release is out so its official ...
http://www.irextechnologies.com/about/press
check out also the changes to the irex website:
http://www.irextechnologies.com/
http://www.irextechnologies.com/mobipocket
http://www.irextechnologies.com/products/content/books
http://www.irextechnologies.com/products/content/RSS
btw ... it seems you can read the RSS feeds from mobipocket on your iLiad, and guess what mobileread is one of the RSS feeds available in mobipocket to which you can subscribe