So, new tanks available in the research lab now!

5+ Panther/M10 - Looks like it's claim to fame is that it's a cheap 3G to deploy. Fills the same role as the Super Pershing but beats it for cost effectiveness, in theory.
Active - Gain +50% damage, +35% armor, +30% evasion for 15 seconds.

4+ T-70 - Produces an area of effect that increases defense 25% for 20 seconds. Somewhat poor in raw stats compared to the M24Chaffee. Three G deployment.
Passive - Basic attacks inflicts a -8% armor debuff for 10 seconds, stacks up to 5 times.

4+ SU-152 - An artillery piece dressed up as a tank destroyer. Having both 50% base penetration and a blast radius of 5 on one tank is a solid combo, but costs 5G to deploy.
Active - Fires an explosive shell that deals 150% damage.

I'm unsure how quickly or frequently the active skills can be used.