I understand that the i5 is better for most of today's games, but I'm wondering if the two processors will even out at the 3.6 - 4 GHz mark, or maybe even gain an advantage over the other. Would the i5 still dominate today's games at this higher clock speed?
Games TODAY don't really utilize the extra core...but games TOMORROW will make more and more use of the extra cores, especially as they become more prevalent in high-end systems. Many development environments are now making use of programming techniques (i.e., threadpools, etc.) that make it easier for programmers to spawn multiple threads as needed without having to recreate the entire framework from scratch.
GPU is the main power games are going to look at. as games progresses GPU will eventually improve in terms of speed and graphic. that being said GPU will bring its own Cores dedicated for games. even tho cpu does helps.
As a rule of thumb, you can say that a vast majority of games is GPU bound. As such, the CPU's influence is limited to giving the GPU 'room to breathe'. This means either will provide roughly identical performance.
The i5 will have the edge in games as they tend to be poorly threaded, meaning Intel's clock for clock advantage is more important than the extra cores AMD offers. In the future, games will be threaded better, but present games rarely go beyond 2-3 cores. As such, we're still years from 6-core optimised games.
The only fly in the ointment for Intel is that 1156 is dead. The CPU's currently on the market for it are the last to come out (Sandy Bridge uses a new socket with 1155 pins, which is rather lame). AMD's AM3 platform on the other hand, will support new CPU's for years to come.
So with upgrading in mind, I'd recommend the Phenom II x4 965. Older than the new hexa cores, but better than the 1055 (clock for clock advantage) and equal to but cheaper then the 1090. Compared to the i5, it's equal at stock, but loses when overclocked (although not by enough to make a huge difference in gaming performance).