Well standards are always changing so it'll be pretty hard to always be on par with them. But if we can compare it to the functionality and stability of Mozzilla - then it will most likly take several years.
I believe Mozzilla took a few, and correct me if im wrong but the have, a LOT of developers. So dont expect an Mozilla or IE compeditor anytime soon.
Unless of course its ported to Linux and promoted a bit as a light weight browser

. That could be very popular on the linux front and spur development - then different teams can share source and so on.