The worry I have with our version of the T-34 (76.2mm gun version) is that:
1) Comparing the T-34 to PzrIV guns, the PzrIV should out-penetrate (ie chance of getting a penetration whereas the other gun cannot at a similar range) the T-34 by a good margin at long ranges
2) the T-34 does not have any real anti-air capability. Some people may mention the coaxil mg, but the fact is that using a coaxil for AA work is, IMHO, rediculous due to both the amount of time to turn to the target, target acquisition, and limited elevation.
This is somewhat offset by the speed of the T-34 (~10 mph faster than the PzrIV). The slope armor may also have some unforseen impact in AH above what I expect, but I haven't messed with the T-34 yet, so I have no way of judging its effects.
I am hoping that HTC will decide to bring in the T-34/85mm version soon since it SHOULD-ie I am guessing on this-be easy to model. I say this because the hull is the exact same one on the T-34/76 that we have. All they would need to add would be the model of the turret, turret armor data, and 85mm gun data.
Furthermore, although it would be faster and have a better gun than the PzrIV, it is 1) not up-armored from the T-34/76 [according to what I have read], 2) it would have a good/excellent chance of killing PzrIVs at long ranges, and a significantly better chance at killing Tigers. Furthermore, without any pintle gun (AA mount), ANY T-34s will always have to worry about enemy aircraft...and T-34s are going to be driving around in a game dominated by aircraft.
Having said all of that, I do believe that everyone should take time to actually test out what the T-34 can do in the game before they jump to any conclusions about it's viability in the MA.