Much like in Resident Evil 5 where between chapters, you could purchase ammo, items, and weapon upgrades, in Resident Evil 6, Skills can be purchased. Skills vary from weapon attack bonuses to defense bonuses to increased ammo. Some Skills can also be leveled up for increased effectiveness. Skills can be purchased with Skill Points that are obtained by killing enemies and finding items.
Players can equip up to three Skills at a time in Skill Sets. At the start of the game, you can only have one Skill Set, but by clearing any one of the scenarios, you gain eight Skill Sets. Players can switch between Skill Sets at any time in the game (Note: The game does not pause when switching between Skill Sets, so do it when in cover) to give a more tactical edge depending on the situation. A damage and defense based Skill Set for boss fights, a ammo and accuracy based Skill Set for normal play, partner bonus based Skill Set for co-op play etc.
Speaking of co-op play, Capcom has announced that Resident Evil 6 will support off-line split-screen co-op play as well as on-line co-op play (that's a lot of hyphens).
Resident Evil 6 is scheduled for release on October 2nd.