I just can't resist
throwing a wrench in the works on this...

BTW, I agree that a mobile-oriented option would be grand, if done 'right'.
I use an Openmoko FreeRunner, (480x640 or 640x480 resolution) with one of: Dillo, Fennec (mobile Firefox), Firefox, or an as-yet-unnamed webkit-based browser.
In another few weeks I'll have my new carputer system up and running, 7" touchscreen in-dash replacing car stereo, where I'll be running primarily Firefox. (this is pertinent to the topic not because it's mobile but because the screen resolution is 800x480, which is the high-end of handheld resolution - if/when the 7" ipod touch emerges it will likely be similar)
With a few exceptions, most 'modern' browser-sporting cellphones have two significant needs: smaller (or at least either optional or more carefully laid-out) images, and no dependance on Javascript and CSS. Forums present an additional need for the avatar image and accompanying text to be laid out 'better' (E.G. 'inline' instead of beside the post) for small-format display. Many mobile browsers support CSS and javascript, but heavy utilization leads to unbearably slow display/update, since the processors in most phones simply aren't up to the demands of modern Web2.0 toolkits. (If you don't know then just trust me - this is what I do: network administration at an ISP, software development, and Web2.0 app development)
j
PS - I occasionally browse with the unidentified browser builtin on my samsung T509, but that's such an unbelievably unrewarding experience, with about 24-character-wide graphically-challenged display, and no javascript possible, that I usually reserve it for a handful of sites that I've specifically written to work with that incredibly limited capability.