Hello Sajid,

You can find a roadmap here Keynote: Odoo 9 New Features , Odoo Strategy 2015 

Just as v8 focused on a major re-write of the Warehouse module v9 will focus on a re-write of a specific module: Accounting.  You can participate in the upcomming discussion here.

Also odoo has been posting R&D Twitter and Facebook posts with screenshots of things they are working on.

Here is a google search of the most recent ones.

Ref : https://www.odoo.com/forum/help-1/question/odoo-v9-roadmap-and-new-features-64262