Which one do you think should I pull the trigger on guys? HD6990m is nice, but its just doesn't giving me the fist, kinda has to lower the graphic settings in Battlefield 3 and many other games in order to achieve flawless framerates, and if my speculation is correct, we should be able to fiddle around with the voltage with a GTX680m (since you can overvolt GTX580m, which you can't do with a HD6990m) and achieve extreme clocks

Or should I just get myself a 32GB RAM kit of Corsair Vengeance DDR3-1600 CL10? So no matter what game I play, the entire game data will be transfered from HDD to RAM when I'm playing it, so there will be no loading time xD

Or, should I perhaps wait for Windows 8 to be released, and then buy a Corsair Force GT 120GB SSD for boot drive and perhaps a couple of favourite games (Skyrim :P) to significantly reduce load time and achieve boot time of under 9 seconds?

ok, well hard to chose between these options cuz they are so different... 32GB is useless. Its the biggest waste of money when it comes to gaming. 4GB is enough, 8GB is overkill.
SSD reduces loading times but does not affect the actual gameplay, its a good update but not essential when it comes to a gaming rig.
So, if you want best gaming performance, it all comes down to your GPU.

I'm with krishnooof on this one; when it's gaming we're talking about, the GPU always takes priority.
Although it may be on heck of a long wait.

If it's all for gaming, then better GPU will surely be better than the other option

32GB RAM maybe is a bit redundant, but it does have its own appeal xD

and what flusters me most of all, is the option to put an SSD to dramatically reduce boot time seems nice, but I really want to overclock my GPU much higher, which I can't do with a HD6990m >.>

GPU all day every day! 32gb is overkilling overkill. Windows 8=NEVER!!!

Yeah, if overclocking and GPU improvements is your priority, than definately wait for GTX680m, but like Eirreann said, it may be a long wait. Very long actually.
SSD is a great update, best would be SSD for windows and most used programs + HDD for games and storage

I have a 6990 and I play all games on max settings including BF3. I see no issues with it I will log on right now and see what I get for FPS as i haven't done that since I first got the game and can't remember

EDIT: Using Fraps I turned on some BF3 64/64 on map and my FPS was 45-50 which is flawless enough for me