i reckon a map glitch will come first as Prestige/Leaderboard hacks will have to be developed which could take a while, on the other hand map glitches will be found quite easily by the freaks that stay in all day with no life going to every inch of the map to find a glitch which will get patched withing on hour like treyarch.
wall breach, usually when the exploiters buy the game one group focuses on glitches, other group try to mod ect.
and usually finding wall breaches and shit is quicker.