My current I-94 card expires on 7/31/2011 and my H1B extension (I-797 with attd I-94) is approved from 9/2/2011, what will be my status in-between (8/1/2011 thru 9/1/2011)? What should I do now?

My Case Summary:
* Current I-94 Card expiry - July 31, 2011 (received at POE on 2/12/2011).
* Current I-797 validity - Mar 2, 2009 thru Sep 2, 2011.
* Approved I-797 Extension (with attached I-94) validity - Sep 2, 2011 thru Sep 1, 2014. (same as "Requested Employment Date" on I-129)
~ Extension Applied on 4/1/2011;
~ Current I-94 card number listed in I-129;
~ “Date Status Expires” on I-129 is Sep 2, 2011;
~ Extension Approved on 5/12/2011;
~ I-94 on approved I-797 extension has the same number as current I-94 card
* Current H1B visa stamping expiry is July 31, 2011