Ms. Pac-Man/Galaga Class Of 1981 (V1.05, V1.06, V1.07, if they exist) Jr. Pac-Man (turbo speed dump)
Full emulated sound and/or speech support for: Gorf Wizard Of Wor Q*Bert Q*Bert's Qubes Reactor
Miscellaneous support: Full access to every service mode not currently supported, especially sound tests. A rewrite on the rom search engine to prevent slowdowns (ex. MAMEUIFX32) Save state support for remaining games that don't have it.
I'll make one more prediction: At least half of all the NEO-GEO will have to redumped, again.