You don't mention Pfizer, Merck, Takeda, Cellgene, etc.
There are many big Pharma or Big Biotech that would be happy to expand into CML, GIST, NSCLC, etc.
Any of these and others that are sitting on too much idle cash would feel obliged to jump start their pipeline with proven and likely drugs, a faster and more effective R&D platform, etc. that would come with acquisition of Ariad.
I have no idea if anyone is negotiating with ARIAD, but I would be surprised to find out that none are. I don't think that the company would accept an offer until after the new patient Rx numbers, and more data on safety, GIST, NSCLC come out, as leverage for greater valuation.
I think that late 1Q early Q2 of 2014 will be very interesting for this company.