Oh yeah. Custom nose art on my B-17 pretty please. Even if they implement a solution like in the Halo series or Rock Band where you can create custom logos and armor/clothing based on an existing palette of options.

The Blade Corner
 

Here are some of my thoughts and ideas...

STRIKE: I would like to see a carrier fleet with DD escorts and CA and CL escorts shooting off all kinds of AAA defending the obj. I say this because in IL-2, on the italian catania map and the British map, everyone always says something about how cool that something on the ground (or in this case the ships) shoot back. I think this would add a complete new dimension to strike... ie, more people would play it.

Scenario battles: I think it would be awesome to relive particular air battles in the pacific. It would be cool for such depth as: flying the same aircraft for the chosen faction and island cover to fly behind to lose bandits.

The hated "reinvite everyone after the match" problem: Everyone knows that in birds, one room can fly 16 pilots. An Xbox live party can only hold 8 pilots... This makes it very difficult to keep everyone on the same page and together. The loss of communication between players influences less interest in the online mode. Therefore i believe that after a match, all players and redirected to the room they left.. BUT! with the option of changing game modes and year, weather.. etc in lobby. I think this would make things WAY simpler.

+1 . Also give the host the option to have shared coms, so both teams can hear each other. Or better yet, give each player the option in game of transmiting to friendly only or both friendly and enemy. That would remove all need for party chat.

+

-Cockpit view in the Hanger with information about what every gauge is for, it's really difficult to know what every gauge is for in some planes, so getting intruduced to planes in the Hanger would be very nice

-The ability to set 0 enemies in the Training mode, so that it becomes a free flight mode, some people can practice maneuvering the plane and landing/taking off, or maybe just have fun....

I would also like to say that the "Training" mode is almost completely BROKEN! because there is no friendly planes, there is no interaction between the enemy and friendly AI, no matter how many enemies you have set to fight, they will all follow you and keep destroying you, so adding friendly planes is a very important thing...

I pretty much want what everyone else has suggested, but in addition:

The world seems very lifeless, especially in single missions and training. A lot more radio chatter should remedy this, to make the sky seem more alive, or at least less repeditive. Oh, and stop saying "Open fire!" every time I get within 0.7kms of an enemy, I'll fire when I damn well please!

No flamethrowers!!

but wouldn't that make your plane go faster if you shoot it towards the rear of the plane?;)

No, but it would be useful for when I overshoot an enemy by accident. :-P

How deadly would that have been as a defensive weapon. Anyone know why WWII planes especialy bombers didn't use liquid flamers for defense?

At a guess its because of the high wood content of the aircraft. It would be like propelling a sailing boat by using a handheld fan! :p

A couple of other things:
Westland Wirlwind
Avro Lancaster
De Havilland Mosquito
De Havilland Beaufighter
Grumman Hellcat
Blackburn Skua
Junkers 88

Japanese planes