Android Police first to report
We came to know of this leaked screenshot first from Android police, and this happened to the fore at the I/O conference. In one of the sessions called the “structure in android App Design” Google (not yet sure whether deliberately or not) showed a slide depicting the Gmail navigation drawer which seems to cover most of the inbox. This will make the navigation ibetween Priority inbox and Inbox far more convenient in the gadgets.
Other alterations speculated
At this point of time, we can also speculate that the action bar with be given short cuts like Compose, Refresh, search and other options. There will be five tabs to segregate emails so that your inbox may be more organized- primary, social, updates, promotions and forums. The primary section is meant for mails of all family office and friends, the social box for social media, promotions for advertisements and shopping sites and forums for interacting groups.
Official comment from Google is still awaited.