A few short points I have put together from today's leaks:
In 0.8.6, 105mm HEAT shells (Panzer IV, Sherman) get a bad pen nerf (from 150 to roughly 104 pen), unless they keep "special" heat shells for arty (unlikely, it's not like that now). Bye bye T5 derp.
Also, splash for hightier arty shells gets reduced, roughly by 10 percent. This doesn't have to be a rule, but it's like that with the new T8 GW Tiger P arty, which means the GW Panther and GW Tiger will have their splash reduced too, as they use the same guns.
Oh and as for the upcoming tier 10 Waffenträger E-100: schematics are already made and it's confirmed it won't have a 210mm gun, so (unless it has the same gun as Jpz E-100, which would be lame), we are looking at 150mm L/68 - verdict: most likely more mobile vehicle with VERY high penetration, armor is yet to be seen.