I don't trust the benchmark also. You need to understand, there are only 2 available resolutions and no full screen for the benchmark, meaning if you are scoring low on the benchmark now, maybe your system will be fine at 800x600 or even 640x480, which hardcore gaming nerds will say ******* awful resolutions. I'm one of those people that do not see much of a difference between my analog tv vs. hdtv. Boohoo, it's clearer, but is it any funner? It's like people who watch awful 3d movies for the 3d and special effects rather than having a good story. I care more about gameplay than graphics.
Nobody really knows until the game's release, so please hold on trying to upgrade your system to try to perform to max settings at 2560x1080 until then. You will save a lot of money by waiting just a few months. I would really love to be able to use my laptop which has a GeForce 6150 graphics, which I used for WoW and FFXI. There are a lot of people whose systems come with 6150, especially those using atom processor systems. While it may sound absolutely horrible for hardcore game nerds with their 5870s, every now and then, I like to use my laptop at school or work to take a sneak peek at what is going on in the game, like taking linkshell message on ToDs or auction house or send something to somebody, and yes, I don't mind going 640x480 resolution doing that or even a slight choppiness. When I'm home, I can get on the desktop.
For those on a budget, I recommend you get a 9800 gtx or gts 250, which would be a $100 or less upgrade. They should go down a little bit more by September-December, or get them on ebay used or even new. Wait about a year, and those gtx 470s will have the price cut in half. If you bought your computer a few years ago, chances are, you only need to put in $40-100 upgrade for a videocard.