Charlie over at S|A dug up an interesting document, looks like NVidia pulled a bunch of their claims over the summer:
http://www.usitc.gov/secretary/fed_reg_notices/337/337_932_notice09012015sgl.pdf
(Charlie's story at
http://semiaccurate.com/2015/10/12/nvidia-patent-licensing-devastated-itc-ruling/ )
Looks like perhaps they weren't confident that these ones wouldn't get invalidated on further scrutiny from the USPO. I'm not a lawyer though, anyone got any insight?
Plaintiffs are the so-called "masters of the case" since they bring the complaint and alleged the wrongdoings. A plaintiff can withdraw their claims in certain circumstances. Here it looks like nVidia is withdrawing claims/patents from their ITC complaints because they dont want to get an invalidity adjudication on them. That, or they settled/crosslicensed for that claim. No plaintiff = no case. By extension, no claims = no complaint = no action.
Most forums will grant these withdrawals because they have very full dockets and they dont do extra work unless there are special circumstances that say they should.
Before people in this thread get their panties in a wad, every single major US corporation does stuff like this. This is how litigation works. Its gamesmanship, trickery, strategy, playing chicken. Patent litigation is called the sport of kings for a reason because its even more complicated. But every company that gets sued or sues regularly does stuff like this in the products liability field, unfair competition, trademark, patent, title vii, you name it. There is and always will be gamesmanship.