Kohli may be in form, but isn't he a bit raw for the number 4 position?
Yuvi has the most experience and should be there, but he is prone to failure.
MSD could go there, but he's far more valuable as a finisher.
Raina too has technical issues although he has shown the temperament to be a good number 4.
Whatever way it works out, numbers 4 - 6 should be the trio of Raina/Kohli/Yuvraj in any order, with MSD to follow at 7.
As for reserve batsmen...that's tricky. It would be tempting to have Vijay as a reserve, but given that we already have 3 openers in the top 3, it is a bit unnecessary. He'll only play if one of Viru/Sachin/Gambhir are out injured. I don't like the idea of Rohit Sharma given his repeated failures. Pujara/Rahane/S.Tiwary are untested at Nat level, so to see them in WC squad would be quite a jump. And Jadeja and Yusuf shouldn't be anywhere near to squad ATM.
Guess the reserve batsmen will be Sharma and Vijay. Don't know who will be picked as backup keeper, I guess it's going to Parthiv Patel since he was preferred over Karthik and I doubt Saha will be going to the WC.
That leaves us with needing 6 bowlers. Zak, Bhajji, Ojha, Sreesanth, Nehra, PK. Looks very likely. Yuvi/Raina/Viru/Sharma the part time spinners and Kohli with some medium pace.
So the likely squad is going to be Sachin, Sehwag, Gambhir, Yuvi, Raina, Kohli, MSD, Bhajji, Zak, Sree, Ojha, Nehra, PK, Vijay, Sharma, Patel.
The only change I think we'll see is Patel out for either KDK/Saha, and Vijay out for one of Yusuf/Jadeja. This is tricky, because the selectors might not believe that Yuvi/Raina/Sharma/Viru would do a good enough job as a fifth bowler. In which case one of the two 'allrounders' will play. While I'd feel more assured with Jadeja batting in the top 7, because he can rescue use from a collapse, Yusuf's bowling has been more effective recently. But Yusuf in the top 7, even if it's at number 7, doesn't feel secure, especially since he has been found out. You want your numbers 6 and 7 to be able to haul you out of a top order collapse, and Yusuf has shown that he can't play a long innings at international level. But for Jadeja, on the other hand, his bowling is fairly rubbish at the moment, so while he can be relied on to steady the ship if needed, and we have enough hitters so that he won't be required to accelerate at the end, his bowling might not be much better than just using the 4 part-timers.
Ashwin is very unlikely to get a look in, unless it's at the expense of Ojha, because I don't think India will be secure with either Bhajji or Ashwin batting at 7. Also, it's seems too late of a return for either Irfan or Chawla.
Will be interesting to see who makes the squad at the end.