I'm surprised they kept the same encryption method for the Pokemon data, to be honest...
Partial list of new items:
#639/0x27F, Weakness Policy
#640/0x280, Assault Vest
#644/0x284, Pixie Plate
#645/0x285, Ability Capsule
#646/0x286, Whipped Dream
#647/0x287, Sachet
#648/0x288, Luminous Moss
#649/0x289, Snowball
#650/0x28A, Safety Goggles
#652/0x28C, Rich Mulch
#653/0x28D, Surprise Mulch
#654/0x28E, Boost Mulch
#655/0x28F, Amaze Mulch
#686/0x2AE, Roseli Berry
#687/0x2AF, Kee Berry
#688/0x2B0, Maranga Berry
#699/0x2BB, Discount Coupon
#704/0x2C0, Strange Souvenir
#708/0x2C4, Lumiose Galette
#709/0x2C5, unknown normal item, some sort of wooden tablet
#710/0x2C6, Jaw Fossil
#711/0x2C7, Sail Fossil
#715/0x2CB, Fairy Gem
656~685 are likely the Mega Stones, if anyone wants to poke around. 28 Mega Stones are known, so there may be two more undiscovered in that gap (and it's easier to poke around 30 items than attempt to form+1 all 700+ Pokemon).
If all the item slots are used, there's around 11 or so items still not known, so they may be worth checking out.