Supposedly the "Breacher" and "Strike" Teams are just the flashy names for the different Fire Warrior unit types built from the new kit. From what I gather the "Breacher" teams are the (Pulse) Carbine-equipped dudes we saw that have alternate backpacks - speculated to be Jetpacks - and the "Strike" teams are the default Fire Warriors equipped with Pulse Rifles. It's altogether possible we are actually getting three units from the Fire Warrior box; standard Fire Warriors, Breacher Teams and Strike Teams though I find this to be unlikely. If Breacher teams actually do have Jetpacks to go with their Pulse Carbines they should be a very interesting unit that actually follow the Tau combat doctrines without requiring a Devilfish, something a lot of people have been praying for (though I would be happy with a buff to the Devilfish myself).
As for the Coldstar Battlesuit, we know from a snippet of the current codex (yep!) that it is a Crisis Battlesuit that has been modified to fight in space - i.e. Zone Mortalis. It's entirely possible the Coldstar is simply the new Commander suit used as an alternative to the Enforcer, but I also wouldn't be surprised if it is an alternate build from the new Crisis Team kit. To say I'm intrigued by the thought of alternate Crisis Team type units is an under-statement, though it would follow with the above Fire Warrior Breacher and Strike teams theory.