Yuvraj and Agarkar haven't been so bad that you should consider replacing them for the final by two unproven guys already. Definitely need to play the untested guys against Zimbabwe though, and that means all of them. Bring in Kartik, Raina, RP Singh for Harbhajan, Yuvraj, Pathan/Nehra/Agarkar. Agarkar has averaged 16, Nehra 23 and Pathan 12 in this series, so there's no reason to replace them in the final. Perhaps Pathan or Nehra should be given a breather.
Apart from Dravid and Ganguly, every batsman has averaged 30+ in the series, and Dravid has averaged 48 in 2005 (Ganguly 18 ...). Ganguly won't be replaced by Raina for the final, and neither will one of the three seamers by RP Singh. The only possibility then is Harbhajan and his average of 110 being replaced by Kartik's left-arm spin.
On another note, Dhoni has been awesome, proving his late-innings explosive utility.