Don - I suspect that Ariad is of significant interest to many companies looking for a successful small molecule pipeline. Sanofi, Takeda, Roche and AstraZeneca are just a few in addition to the obvious PFE, LLY, MRK, BMY, ABT and CELG. I agree that A Merck partnership for 534 will be a mistake. Your point that Merck will get all the benefit without having to pay the price is well made. On the other hand, if Rida succeeds, Merck will save at least $1billion over a few year time frame by buying Ariad outright.
Once an offer has been either made or accepted, Ariad will be in play and other bidders can be expected unless the first offer price is at the top of the range.