Yes I agree about the Mishra part. He has shown some qualities and needs to be in the side. In hindsight, I would play Ojha and Mishra in tests. Having said that though one has to have faith in players, and in persuing with Ashwin during his out of form days, it would be wrong to accuse Dhoni of Bias.
I mean remember, when Mark Waugh was woefully out of form and yet the Aussies kept going with him. That is because at one point he had delivered, and thus persevering with him is fine, and it would be totally wrong to accuse Steve Waugh of favoring his brother.