I'll answer briefly now, and maybe update later.
We plan to continue developing the software on the long term, but need to polish the existing set of features and that will take probably 2-3 months with most of the work done in one month.
So I'd consider the "done" stage is when the existing features work coherently.
In the future we do not plan to copy closely any other existing software, but will use the most successful features found in StackExchange, Quora and others.
What I want Askbot to be in the future - a flexible open source platform for the Q&A knowledge management.
It could mean different things depending on the user: a simple fun forum, a customer support application, a portal for subdivided communities to use in organizations or community websites.
We want optional access control features, optional user groups and some other details being optional - so that the admin user could configure Askbot for his/her needs.
Askbot will work as a Q&A forum and a mailing list - users will be able to ask and answer by email as well.
Most of the necessary features either are implemented or are "almost ready".