jury instructions crucial
Today could be the most important, the jury instructions control what the jury can do to the squabbling litigants and they're unlikely to go outside them. Koh would simply ignore them if they did in any case. Expect a tooth&claw fight between the lawyers.
What I want to see is the jury having the opportunity to rule that both sides lose. If there's no option to rule Apples design patents invalid the entire affair was just a waste. Samsung losing on FRAND just leaves Apple forced to pay up a smaller amount... actually forced to hand over real money with no more delay. TBH though I expect them to rule Apple is covered by Intel's licences.
Still, both sides losing would be great news for Samsung. The injunction lifts and they don't collect excessive fees they never expected to get and asked for in retaliation. For Apple it's game over, they'll lose their ludicrous patents. That's got to be good for almost everyone.