9. In some courts, the odds of invalidating a patent are relatively low. District courts exist in which the validity of patents are almost consistently upheld. In these districts, reexamination may be a more likely mechanism with which to invalidate a patent.

This is probably why Pubsplat filed... they (or whoever put them up to this, ARM perhaps) knew their chances were slim to none in court, they have a better chance through the USPTO.    Pubsplat filed for an ex parte exam, meaning PTSC will be included in the review process while Pubsplat will not.