I respect those who think that Ariad will not perform in some meaningful way in the future.
My opinion is different than that and don't think that the "value" of a company (in the eyes of the acquirer) is based on just hard numbers. More so, they are looking at talent, products, developmental processes, science and most of all potential. They are "buying" because they don't have it and for how it might add to/complement their operation as a fit.
Again, I absolutely can see the other point of view which at this point in time has merit. Everyone here wants to make money with a minimum of frustration at which we currently are at the apex in not knowing.
In the way that I think, if I felt so negative about an investment with so little confidence (especially with your historical perspective, knowledge of operations, science, etc and being here a lot longer), I would have sold it and moved on.
We are all different, each to their own and we will see. I admit, I could be wrong and certainly don't have any magical insight. Good luck.