I have a friend who plays Tau in TT game and for what I have seen, they fucking rocks at long range battles: they blast out a huge amount of firepower; the most downside is that they seriously lacks melee fighters (yes, I know the kroots but they end dying very quickly from enemy fire before they could even reach them).

I think and hope that Tau race will be implemented in a future expansion, maybe when the game mechanics and gameplay issues will be already strongly tested.

If you don't know who play, play Eldar or Orks, we have to equilibrate the different faction...

I agree with Creator: maybe Eldar are more similar to Tau in some ways than Orks are and they have also powerful melee units which Tau have not.

One of the keenest tricks and hardest tactics to master with Tau is when to move. When playing Tau and when I've played against the Tau their best games are the ones that keep the enemy at arms length, deploying forward with enough room to step back to keep that combat away for one or two more turns can completely change the game.

You'll probably see Tau and IG in an expansion at some point.

so tired of those posts, please do some research because developers told us that other races will be but not at launch.

Not sure if this has been said in this thread yet, so I will:

Tau don't fit unless the planets we're fighting over are in the galactic east, in the vicinity of the Jericho Reach. The Tau use "warp skimming" for FTL travel. Thus, they move slowly and can't really project power very far from their worlds. This is generally assumed to be only thing keeping the Tau from being a HUGE problem for the Imperium and other major powers since the rest of their technology is incredibly advanced.

To have the Tau take part in a campaign that takes place somewhere other than the galactic east wouldn't make any sense at all.

That said, they'll be in-game at some point.

You forgot that the Imperium and just about any other faction in the game (probably including Craftsworld Eldar) outnumber the Tau to the point that it isn't even funny anymore. The only reason the Tau still exist lies in the Imperium being busy elsewhere; it would have curbstomped them a while ago if not for that.

Excellent point, but that wouldn't be the fluff reason why Tau weren't in the game. That's just the fluff reason for why the Tau, as you say, haven't been curb-stomped by the IoM yet.

Most likely future expansions they really want to add as many races as possible.

They have no reason to be fighting like this to be honest, The Tau want to assimilate other cultures not get into an attrition war they don't have the manpower to back it up.