I agree with Jack. A move like this from Intel to try to control the supplies would get the attention of the anti-trust people in a hurry. Aslo, there just aren't that many sources of SOI wafers out there, so AMD would be put in a real hurt very fast, further inciting the anti-trust watchdogs.
Besides that, as mentioned by Bloomberg's, since a fair amount of Soitec's business comes from AMD, if Intel bought it and cut off AMD, then Soitec would start loosing money. Further, as Bloomberg's point out, Intel has denied interest in Soitec. This puts the whole thing in the rumor and FUD type of stuff.