Since I know you guys are going to ask for it, I'll post the source first: http://forum.worldofwarplanes.ru/index.php?/topic/53180-вопросы-разработчикам/#topmost (have fun figuring it out :P).
Update 1.2 will not have any new planes.
Update 1.2 will bring (most probably a part of) the HD client.
Improved after-battle report as scheduled for update 1.2.
The next lines to be added are the US heavy fighter branch (P-38 and Co.) and the MiG branch.
The map Eastern Front will be brought back when it is further optimized.
Stats of planes in the garage will be modified by equipment & consumables (as in, buying aircraft polish will affect the stats just as modules currently do).
A battle mode much like the 7/42 battle mode in WoT is planned to appear.
The devs are working on allowing players to spectate teammates without having to wait for your airplane to kiss Terra Firma.
A new, WoWp-specific MM may be in the works.
When kill someone via crit (breaking a wing or the tail), the remaining amount of HP of that aircraft is not counted towards rewards. Devs are looking into this.
UPDATE (February 19th, 2014):
The replay function will not be improved further in 1.2 (bugs will be fixed, but no feature will be added in test server patches).
Joystick control scheme is being worked on, expect many changes (soon™).
WG RU is thinking of making a video to show how to setup your settings.
WoWp will model cartridge ejection, for the planes that had it (if I translated it correctly).
While devs are not considering implementing realistic ballistics, they will reduce spread to a more plausible level.
Tier 6 and tier 7 premium planes are planned to be gradually released this year (tier 6 first, then tier 7).
AI controlled Bombers? Soon™.
Clans will be implemented the same way in WoWp as they are currently in WoT. There is much work to get clans released, however.
Me410 with the 50mm cannon (and probably the 262, though it wasn't explicitly stated) will make a return.
The devs are not considering a "ground attack" game mode. (One team has for mission to destroy all GTs, the other has to defend).
GTs' HP will be reworked to be more unique. HP will be based on their size and 'abilities' (EI, moving, shooting back, et cetera).
Devs are not considering the ability to add a plane's gun as a damageable module.
"Devs are aware of the 110C-6" (I interpret this as 'nerf incoming').
Apparently, The_Chieftain (Nicholas Moran) is preparing a plane-centric video. (I'm sad that we had to learn that from the RU forums D:)
The devs are thinking of allowing players to change the increment for engine power (I believe the engine has to be incremented by +-10%?). This is not planned to be pursued anytime soon, however.
Ramming mechanics/graphics will be improved (more varied/realistic destruction), most probably with the introduction of the Havoc engine.
WG does not support third party mods, in the sense that they do not actively build their code to help/allow certain third party features (XVM is what the question was most likely referring to). WG does leave their code 'open-ended' to allow for modification, but does not go out of their way to facilitate modding.
There is a desire from devs to reduce the distance of engagements.