The new Dell 2209WA has a S-IPS panel, which I understand is superior to TN panels. It also sports a 6ms response time, so it will also work well for gaming. It does not have 1:1 pixel mapping, however. How important is 1:1 pixel mapping?
The Dell 2209WA uses something called e-IPS not S-IPS. It is supposed to be cheaper to manufacture than S-IPS and H-IPS panels. What's the difference no one knows 'cause no details have been released yet.
1:1 pixel mapping is not very important unless you are trying to play a game at less than native resolution, but you want to maintain the best graphics quality. Diablo II is an example, it only supports up to 800 x 600 resolution. The Dell 2209WA would stretch that out to fill the entire screen. There's should be something in the monitor's OSD menu which allows you to set aspect ratio which means the graphics will fill the entire screen without stretching the graphics. Thus, Diablo II will appear in 4:3 aspect with black borders on the left and right side.
You cannot play any higher than 1680 x 1050 with that monitor.
It is not a driver issue. That feature is simply not part of the Dell's BIOS. If they were to release an updated 2209WA with 1:1 pixel mapping, then the only way to upgrade is to call Dell and ask if they can flash your BIOS. If they agree then you will have to ship it back to Dell; you will most likely pay for shipping both ways.
If you have an nVidia GPU then you can force 1:1 bit mapping.
1. Go to nVidia Control Panel.
2. Click "Change flat panel scaling" under Display.
3. Select "Do not scale" then click apply.
Now when you choose a resolution lower than 1680 x 1050 it will use the exact resolution you specify which will put black borders around the viewing area.
The HD 4870 is pretty much capable of handling all games at 1680 x 1050. Exceptions are Crysis since the graphics engine was not as optimized as it was in Crysis - Warhead, and GTA IV which is really due to very poor coding. And yes, native resolution offers the best image quality.
I've had my NEC LCD2690WUXi for over a year now and the only time I used the 1:1 pixel mapping feature was to test it out for about 10 minutes. Unless it is a real important must have feature, you shouldn't let the lack of this feature determine which monitor you buy.
Actually, in addition to that, ATI has the option to force it as well. All you have to do is go to the panel in catalyst control center, go to "attributes," check "enable GPU scaling" and use the setting that says "Use centered timings".