Everyone I know feels that ipi will be granted accelerated approval. The FDA cancelled the ODAC for ipi, and said a decision would be made by March 26. I can't imagine that they would cancel ODAC and then not approve the drug. Though it could, of course, happen that way.
The regulatory issues for Ipi and Avastin are different in couple of respects. The data for ipi have shown overall survival benefit, whereas Avastin can't show that in breast cancer. And, the treatment options for melanoma are much more limited than in breast cancer.
I share many of the concerns raised by the author of the blog you reference. Clearly we need a regulatory process that is consistent, transparent, and timely. Moving a therapy from the lab tthrough approval takes a decade or longer. With medical science changing rapidly, this seems a bit archaic. What if we could shave a year off that process? That would translate into thousands of lives saved.