This initial version of the browser will be an alpha alpha release. PC World reports that Mozilla's VP of mobile, Jay Sullivan, said there will be several versions of the alpha provided to the Mozilla community over the coming months. It won't reach a beta state until sometime next year.
Will it be available for any other platforms? You betcha. Windows Mobile will get a version of the browser, too, though there is no word if it will get an alpha version or a beta version of the mobile browser. There was no word at all whether or not other platforms, such as Symbian, will get alpha or beta versions of Firefox for Mobile.
By releasing it to the developers, Mozilla will find out soon enough where the browser's faults are, and will have a good opportunity to receive feedback from those most likely to adopt the browser in the future.
Looks like I won't make the cut to be an alpha tester, but I am very much looking forward to the eventual beta of Firefox for mobile.