Wow… I like Darrell and Andy’s commentary usually but they really don’t know how to play Tau at all. I would look to a more experienced Eldar player to create a list if you didn’t have a Tau one. It’s quite obvious their preference of play style. I can tell all you new guys who might be reading these comments right now, once you get beyond the usual smash and grab tactics you can really screw with your opponents head. Don’t play the game of smashing heads together if you want to play Tau or a similar force. Similar to Eldar, and in some regards Necrons.
Anyway, a lot of the comments have corrected most of the mistakes so I won’t go down that road. Overall I think Drangelion nailed it on the head with his comment. It’s not about shoring up weakness, it’s bring overwhelming strength to bear. With the Tau weapon range and mobility they can focus fire on anything and kill it to a man. The Tau rely on their special rules to win. Not their stat line. The main weapon though for Tau players, are other armies codices. Know what can do what, so you can make proper target priority decisions.
Something overlooked in the video was that markerlights if used as networked markerlight drones are the same type as the controller. So if you stick them with an XV-8 or stealth suits they will count as jet pack infantry… which is relentless and can move and fire heavy weaponry without penalty. It would almost be better to drop the pathfinders and their mandatory devilfish to stick some markerlight drones in there. Also, unfortunately Andy was right, Tau HQ generally suck… if you look at them as warriors. Better to think of them in a support role. Kinda like Imperial Guard.
Make your mandatory commander a markerlight chauffeur. Stick twin linked flamers on him as well and you got a cheap commander lending some Ballistic Skill upgrades or more importantly removing enemy cover saves. And if things get too close you can jump him forward and flame a few guys down and sacrifice him for the cause.. of keeping your gunline intact. (you can make him good, but only at high point cost. I think the argument is you’re not getting your moneys worth).
Until then you can hide him in a unit. Or give him a bodyguard if you want to do add some more ML drones… gets a bit expensive then tho. But they can move and fire and you can hop them behind terrain in the assault phase to avoid getting shot.
The XV-88 Railgun suits are really nice and powerful, but one thing they don’t get over the Hammerhead is the submunition. S6 Ap 4 large blast… perfect for taking down large hordes.
One thing over looked if you want to keep your firewarriors safe for a turn or two from assault instead of ork boyz are the Piranha. They can take flechette dischargers. Any model attacking them will take a wound on a 4+, before they resolve their attacks. Plus they can drop their drones off near the end of a battle if still alive to have a quick denial unit. Suddenly your opponent who may have been up by 4 is could be down by 2… for example.
A better choice for Tau if you were going to do something unusual would be Necrons. Use warriors or Immortals to bolster the Tau gun line and act less as a wall. than a shield. a regenerating shield. Imagine a Tau player showing up with 3 railheads and a Monolith… 😀

@drangelion : guide is good but limited firewarrior unit size makes it not so effective as it could be, especially since they can boost their BS to 5 with markerlights. Doom is the killer one. A Farseer on a jetbike, drops doom on 30 ork boyz and 70 firewarriors can re-roll to wound with their pulse rifles. I’d like to see a unit of boyz walk away from that. Tau are superbly equipped to deal with hordes. Especially now since they can walk away and still fire 30″. Adding Eldar to the mix makes them even more so. And anything that can handle hordes usually has enough firepower to handle anything else. usually. 😉