Well i don't know what resoloution your gaming at. If your gaming at 2560x1600 and above then the bottleneck is not bad at all. if you are gaming below that resoloution your card is most likley being bottlnecked by 10%-20%. That card you have is extremely powerful so you would be able to get by with it until later when you can afford an upgrade after the CPU/Ram upgrade.
Bottleneck? What are you talking about? The i7 920 is equivalent to the i5 2500k in games. You have ZERO bottlenecking going with your current configuration.
I would sell your GTX590 and upgrade to something else so you can get performance you're happy with. The i7 920 still has a long life ahead of it so you shouldn't worry one bit. Perhaps upgrade when Haswell hits the market; not now.
GTX 690 is roughly 10% slower than a GTX680 SLI configuration. an i5 2500k at STOCK will only bottleneck this SLIGHTLY. You're talking performance numbers you won't even notice.
Now taking into consideration what I said earlier, i7 920 = i5 2500k performance (roughly) in games, I am almost certain that OP won't have any issues with bottlenecking. Even if he does run into a scenario where he can't take 100% advantage of his GTX690, he will STILL get more than playable framerates.
There is no reason to upgrade an i7 920 if all you're going to do is game. It would be best to wait another generation or two of CPU's to upgrade as the i7 920 still has plenty of life in it.
I think i'm going for the GPU upgrade then, GTX 690 or the Powercolor Radeon HD 7990 . What are you guys thinking of my motherboard (pci 2.0) and the GPU being pci 3.0. Will it affect lots of performance? Thanks