Right now it seems united opposition cannot counter BJP. over the time if BJP's progress reort unsatisfactory , then BJP  will be in dire straits.

I think every government must have ten years time to judge and if people satisfy with performance then it is OK other wise alternatives could be chosen, 

Everything has a time. If the required time s not given to any party it becomes difficult to survive. If its otherwise   people themselves dethrone a non -performing govt as it happened in the last elections.

There is famous quotes about united we stand and divided we fall but this does not applicable to political systems. 

Latest news is that merger is differed. There's time still to form united front.

Sp said it is not possible for merger before Bihar elections, and it is seen from distant. 

It's an old news. That the merger is postponed for now. It came in the news 2 days ago. And I posted about this in my earlier threads of this discussion.