I don't see Binny playing in Australia. When we go to New Zealand however, there is a chance that Binny might come in for Jadeja because there won't be be much spin from the surface and grounds are much smaller compared to Australia.
Jadeja bowled really well this game (figures don't really show it, just like how it happened for Ashwin last game) and as Aman said, he saves you lot of runs on the field. To be fair to Jadeja and Dhoni this game, they had to contend with possibly the world's best bowlers in Steyn and Morkel at the death overs. And Jadeja took on the brutal fielder AB De Villiers and got run out in the process of turning the strike back to Dhoni today. And it worked, where Dhoni plundered 3 consecutive fours off Parnell in that over.
I am not a great fan of Jadeja, but he should stay.
If India top Group B, we will play the 4th team from Group A. Which could be either England or Bangladesh (or Sri Lanka if they play really bad to end up 4th). Not sure if we can avoid Australia till the final. But an India vs Australia QF looks unlikely as of now. And I believe NZ will most likely top Group A.
I certainly hope so!West Indies vs Zimbabwe today. Can we expect the second upset of the World Cup today ?
Australia are hard to beat in their conditions, but they are not invincible. No team is invincible in this tournament, not even NZ. The Aussies of 2003 and 2007 were a lot closer to looking invincible.