This is just a guess based off the live letter interview and the item list in the patch notes, but completing the extreme primals each week will likely get you the "Rowena's Token" to trade in for any of the new ilevel90 weapons. I assumed it'd be like the relic quest and you have to complete the primal line with each job, but if the token is given like I think it is then this will make gearing other classes weapons fairly easy.
By the way, anyone know if they are nerfing Titan HM too? I didn't see anything about it, but the ilevel requirement for it is listed as i60. That seems so low, most groups need a decent amount of DL.
If they are not nerfing then it makes me wonder just how far above the required ilevel the Extreme modes will "realistically" be.
Subtle nerf, they're changing the way the servers update data during Trials/Instances, so that there's a little less latency. It should make almost everything, "marginally," easier. However you have to be cutting things PRETTY darn close in the first place for this to really affect you. We're talking fractions of a second improvement.