What is S3 worth now that key patents have been invalidated?

Litigating Apple notes that on the very same day that an ITC administrative law judge ruled that Apple infringed two of S3's patents, the USPTO made initial determinations that the relevant claims of the two patents are invalid due to the existence of prior art. Apple can ask the ITC to review the infringement decision in light of the USPTO's invalidation of those patent claims, as there can be no infringement of an invalid patent claim.

HTC’s $300M purchase of S3 and their five patents was reportedly a defensive move against Apple’s early victory in their patent war. Was there a contingency clause built into the purchase agreement that negated the deal if key patents were invalidated?  If not, was there a strategic fit other than as a hedge against Apple? If not, what's it worth now?