An implemented weather system would be totally awesome! Cant wait to finally fly through cloud cover with rain dashing against the cockpit.

But honestly, there are a lot more urgent things to work on IMHO!
Anyway what I would like the devs should work on now is the following:
1. Just a little further optimization in terms of stuttering (i STILL have stutters in game, but my fps are never less than 30 fps thx to the new medium effects setting... avg 50 which is great basically, but there is still a "decent" amout of stuttering low level) Apart from this I am quite happy with the performance right now! If further optimization to remove stuttering isnt possible without dumbing things down, i am fine with that too! as long as better hardware can erase stutters etc eventually its okay for me!
2. steady work on the FM/DM, but they are on the right way I think! (this includes correction of some mistakes in cockpit modelling as well, like the Blenheim boost gauge, the many many minor flaws in the 109 and 110 cockpit (see bugtracker)and in other planes)
3. bugfixing of the long list of minor bugs which are annoying due to the sheer amount of it (retracted landing gear online; AI gunner control; weird red graphic bugs in cockpit when wounded; objects can be seen through clouds etc.)
4. Fully operational Communications system
5. Bring back high clouds, maybe canopy reflection in the distance and better view of distant objects like buildings (bombing is a little hard right now, because the targets appear way too late)
6. Enhance and improve sounds (sometimes missing AA and enemy gun fire hit sounds; more ambient sounds like tweeting birds, working sounds on an airfield, crushing waves etc; sounds of smashing und crushing glass and gauges when your cockpit is hit) In general: I want just more sounds to get this thing ALIVE so it feels real!
7. Physics: broken parts of another aircraft should damage you if you are hit by them (this would revolutionize the combat in terms of caution by an attack etc)
Tree collision model (this would revolutionize emergency landings and low level combat)
8. Some corrections of the netcode (this includes the landing gear retracted bug and other flaws while flying online)
This is my personal wishlist for CloD. If they can manage to correct these mistakes, I consider this game as "complete and totally awesome to play"

I know this seems to be a huge list, but some of this bugs should be pretty easy to solve while others take more time. Anyway this is no waste of time for the devs, because nearly all of it is necessary for a successful sequel either way!
Every other extension, like a fully functional weather system (maybe dynamic, but not necessarily), navigation and landing lights or the MUCH NEEDED Coop System has time till the release of the sequel... of course then all new features should be applied to CloD as well!!