The Harvard Law School Forum just put out this piece on appraisal, wherein attorneys from Debevoise & Plimpton discuss the current state of Delaware appraisal jurisprudence and seek to place the key recent decisions in the context of the overall arc of appraisal law.  The attorneys close with this observation:

So where does this leave us? First, we are meant to put significant trust in efficient market theory, relying as a starting point on both market price and, if resulting from a strong process, deal price. Second, we need some additional guidance on what will or will not jeopardize initial reliance on deal price. And third, we still need a fair amount of guidance on what, if anything, to subtract from deal price in a sponsor deal, on what to subtract from deal price in a strategic deal, and on what, if anything, to add to market price in either type of deal.