They do need a defensive boost, though I'm inclined to say it would take at least 2 armor. Right now, lings or marines (or roaches or...) absolutely, positively eat  thors. 1 extra armor would only change that slightly. (I think) it wouldn't change much vs heavy hitters, which I think the thor is a little better against.

i'm inclined to say they need 1 armor and an upgrade to their special skill and +1 damage vs air, or 2 armor and +2 damage vs air rockets. Any air vs ground fight is going to destroy a thor easily. Any cluster of small units is going to destroy a thor. Right now, the value in a thor is having 1 or 2 in your army, because they are well ranged, and keeping them in the back to deliver hits. (which seems so backward, since they are big tough-looking mechs, they should be TAKING the hits)

No I didn't opt in or anything, just got an email ,here is what it said

Congratulations, this is your invitation to the beta test for Blizzard Entertainment’s StarCraft® II: Wings of Liberty™! You are receiving this email because you attended a special Blizzard Entertainment event, participated in a related contest or promotion, or have otherwise been selected to join the beta-testing process. This email contains your beta key along with instructions on how to get started.

The last event i attended was blizzcon 07 so i'm pretty sure that's not it. Must of been randomly sent out to some WoW players or something.

Or I am just that awesome.

I think they already have armor 1. Honestly after you give them 2 armor upgrades they can own with the proper support. They crush air units though. Clusters of small air units go down amazingly fast. Splash damage and a bonus to light armor on their AA attack is plenty brutal. After I got the second armor upgrade for them they were slaughtering any ball of Mutalisks the opponent could muster while suffering no losses. And that was without proper SCV support.

I got my key and have been playing for a while. I'm decent with protoss and zerg now, haven't touched humans.

I'm still in the war3 state of mind (more micro, less units) so, for my end game I always forget to make like 15 gateways (I usually have like...3) and thus, I have less units and get pwned.

It'll take some time for me to get used to it.

Well, they crush air units like mutas- if you're dealing with BCs or Carriers or void rays etc they're only good if the opponent both clusters, and ignores them and goes after everything else.

But really, if the opponent is using mutas on humans, they have bigger issues. Other units that crush mutas:

Marines

BCs

Vikings

Missile turrets

Basically, any terran anti-air is a good counter to mutas... they seem to be designed to make a toss' life miserable, though. My concern about thors is their versatility - they rock air clusters, and heavier short range units (zealots, ultras) but they are most vulnerable to the units they are most likely to see, masses of tier 1's.

I realize they have their role, but they're 300 minerals and 200 gas... uber expensive all-purpose units usually don't have those kinda weaknesses. If you build a force of say 8 thors, nearly any ground force equal to less than 2/3 it's cost(and DEFINATELY a lower gas cost) is going to destroy it. Crush it. The advantage of teching to a tier 3 uber unit is minimal. Meanwhile, you spend the same moneyand time to get 6 BCs, and you have a deadly, versatile force to be reconned with, that has a huge advantage in any theater. they are NOT vulnerable to any small, cheap unit, and they can stand toe to toe with anything heavier. Infact the yamatoes generally give them an advantage vs heavier units too. Mutas seem to be the only reason to invest in thors over BCs.... (or if you happen to notice your opponent has inexplicably built 40 corrupters before you build a fleet?)

Thors won't have a problem against tier 1 if they are properly protected.

I m loving those reps on youtube

you should check them, there is a quite good fight with mass Thor kicking zerg (but losing so much Thor unit in the process LOL)

check HDstarcraft

BTW, if anyone wants to share a beta key ...

Marines are no where near as effective as Thors in taking out Mutalisks for the same level of investment. 3-4 Thors can wipe out stupid numbers of Mutalisks without breaking a sweat. Marines are going to take heavy losses, take longer to kill them, and not have the same range of protection. Vikings don't even come close to being effective against Mutalisks though. I don't know where you got that impression. I watched 8 Vikings get crushed by a relatively small swarm of Mutalisks, while 3 Thors took out more, and only lost one unit.

Battlecruisers also cannot be created as fast as Thors. Not even close. Thors have a 60 second build time vs 110 seconds for a Battlecruiser, and it takes longer to even get them! Yeah, I would take a Battlecruiser over a Thor on a one to one basis. It takes a lot longer to get them, build them, and make them in large enough numbers to take down a Mutalisk swarm.

Carriers are a funny one for them to fight. Targeting the ship themselves will mean the Thors are in serious trouble. Having them take out the interceptors helps level the playing field. I wouldn't build a Thor against Protoss though. Going for a ground war never really ends well as once they start producing Collossi you lose on ground.

tagging for later voewong of awesome reps.

I'm not saying those others are AS effective as thors at taking out mutas, just that they are effective - and often more versatile.

As for vikings not being effective against mutas... seriously? vikings do nearly twice their damage at 3x their range. Are they effective at 5 to 1 odds? No. But they're only a touch more expensive (50 more minerals, 25 less gas), so if the opponent has 4 or 5 times your forces, you're in for a beating. But the advantage of vikings is that they're fast and have matchless range. They shouldn't sit and get eaten by mutas.... they can stay back, pick off a few for free, and back off if chased. They can pull the mutas into ground forces or force them to retreat. if you watched 8 vikings get crushed by a relatively small swarm of mutas, you watched a novice using the vikings. Aside from which, I doubt you'd see a lot of mutas if you're terran anyway, as they have so many units effective against them. mutas are primarily deployed vs toss, who they terrorize.

As for thors against carrier interceptors... seems like they'd be good against those... I wouldn't know though, as I have yet to see someone use them. (Except in maybe one non-ranked FFA game)