Just updated now... I think they may have finally added some of the things I required before I would consider switching from Firefox. And flipping Nora, that scrolling is awesome.
Of course I will need to spend some time in it before I can properly form an opinion.
If they can do the following
(1) get rid of those annoying UI clutter for options
(2) make the default keyboard shortcuts to be like FireFox and Chrome (yes FF and Chrome's Keyboard Shortcuts have become a "standard" in my opinion)
(3) Some really useful AddOns like AdBlock and FireBug for Opera
Then, I would be a converter. I feel like this Opera 10.5 is the very first version of Opera that I actually enjoy using for the first time ever!
Previous versions sucked and was not the right browser for me.