He said M&M vs. Zerg, he said nothing about Tanks or SV's, and yes I have heard of micro, but it wont save your ass from 8 burrowed Lurkers if you went M&M and I would have backup Scourge like I always have, just incase someone gets the idea of Irradidate.
A complete guide to Terran vs Zerg for the people who just cant get it:
9 depot 10 rax 11 rax, marines from the start. Refinery at 12, factory as soon as u get 100 gas. Academy right after the factory. Attack as soon as u get 12 rines and 2 medics (if he masses lings get some bats). If he sunkens up at fast exp pull back. Add a comsat station as soon as the accademy is done. U need it for early lurkers and for scouting. When the factory is done, get a starport and science facility right after the port is done. Dont bother to build tanks this soon. Add 1 or 2 more raxes and keep making marines and medics. If he makes mutas, make a bunker by ur SCVs. Start making tank backup and research irradiate at this time.
In mid game, get an expansion. Keep scouting the map with comsat stations (these should be hot keyed), u should ALLWAYS know exactly where the enemy expands, and zerg will have a lot of expansions. Keep making mass M&M and tanks/vessels for backup. Keep killing enemy expansions, either with frontal attacks, cliff dropps, or M&M drops directly on the exps. Micro the vessels and kill scourges with marines.
U should take the mineral-only expansion too because zergs tend to get a lot of units in mid/late game. Bunkers should be added around ur exps to hold off attacks long enough for u to send backup and transfer SCVs.
In late game the enemy will either:
A) Keep massing hydra/lurk and add guardians. To counter this get extra science vessels with irradiate to kill guardians.
B) Ultras + lings in dark swarm. To counter this, get extra tanks.
Definately the Goliath. In almost any game it can dominate. Especially in UMS games but if your playin melee its different. If you get a lot golz and you're up against any unit you can most likely win over them easily.