Regardless of the material, everything you have now will only be useful up to level 60. Still, I would keep one stack of everything, just in case. Your Tome of Secrets will be converted into Demonic Essences which are much more rare now. I believe Brimstones are still used for Classic Legendaries and Sets. Basically, unless you really need money, I would keep everything. Otherwise put them up on the AH if they still worth something.