Seeing the form Sehwag has been in recent times, you would be absolutely stupid and terribly harsh if you ask for him to be dropped. After his comeback (last year), he has been a changed batsman in all formats. He has forged a great partnership with Gambhir that is now being called arguably as the world's best. He has scored runs overseas in recent times and has helped India win tests abroad. Captaincy clearly affected his game at Napier and the comeback of Dhoni will help him quite a bit.
I would drop Munaf Patel and bring back Balaji. I know some hate Balaji, but seeing the way Munaf plays his game, even I would go out there and manage to bowl something rather than see Munaf play cricket. Its laughable! Two changes for Basin - Dhoni for Karthik, and Balaji for Munaf.