Undoubtedly no version for Firefox for iPhone is planned, however a Blackberry port for Firefox is also difficult due to its Java-based OS. Android users however might see a Firefox version as such versions are undergoing testing and development.
As Firefox enters the mobile market, it does not leave behind its powerful add-on centric roots. The Firefox mobile browser promises extensibility and in fact launches with the new Weave add-on which is Mozilla's official synchronization system for Firefox mobile and desktop.
It is amazing how much of Firefox you get with Firefox mobile, the browser while meant for mobiles packs in almost all of Firefox's salient features. Even so the browser manages to provide an interface which is relevant for the current touchscreen mobiles.
The Mobile interface for Firefox hides everything till you actually need to use it, saving all your space for the interface of the website that you are browsing. Most of the interface is hidden just outside the visible area and is accessible with a simple slide.
By sliding the interface towards the right you get access to all the open tabs as thumbnails of the open windows. Sliding the page to the left will reveal on the right side, the back and forward history controls and a button a bookmark the page.
An settings button is also visible on the panel at the right, which takes you to the interface for managing you browser settings and configuration. Here you can mange you installed add-ons and search for add-ons in the catalog. You can also manage your downloads here.
For entering URLs, an address-bar is appended to the top of the page which is available when you scroll to the top of the page. Since the interface supports kinetic scrolling, you could easily reach these interface elements by the flick of a finger.
Important features of Firefox such as the password manager and popup-blocker are available in the mobile version too, and missing ones can be added back with the help of add-ons. The add-ons gallery already has quite few add-ons which work with the mobile version, and more will be available soon.
While plug-ins support is possible in Firefox Mobile, it has been disabled in the final version due to performance concerns. In Mozilla's tests, the Flash plugin performed fine for websites such as YouTube, however it was detrimental to a good browsing experience when using websites with multiple plug-ins. An add-on is in the works which will allow enabling plug-ins on a per website basis.
Firefox's mobile standards support is at parity with Firefox 3.6, so yes even complicated HTML5 applications such as Google Wave will run on it. Support for features such as location aware browsing and off-line support means that websites such as Google search and Twitter can use you location data, and web application which support it can continue running even when you don't have network or internet coverage.