A few points to help put this in context: 1. Technically, the USPTO hasn't yet "invalidated" the patent; it issued a first "Office action" in which it stated that all of the patents claims were unpatentable in view of varying combinations of prior-art references. 2. Institutionally the USPTO is very much aware of the significance of reexamination for a patent in litigation. 3. The Office action was signed by a "prima…
This seems to be one step of a number of the way to invalidation but far from a knock-out blow for the whole patent YET. There is a range of possible outcomes including total invalidation, the patent being upheld and perhaps most likely some claims being invalidated narrowing the scope of the patent and making it easier to work around it.