A need for SLI?

Yes there will be but a single fast card will suffice for that resolution

It depend on your card too...
Like Mod said, you'll better with a single powerful card...

It depends on what card you are looking at. I see your info says you have a 8500GT. Is this the card you are going to SLI? I did a quick search and you can expect around the performance of a single 8600GT with (2) 8500GT's in SLI. Is it work the trouble? I always try to go for a single card solution when I can. There are a number of headaches that can come along with dual card setups. You may find it easier and less stressful to sell your current card and get a better performing single card. I have found this to be the best route in alot of cases. Unless the dual card setup will be far cheaper, then it might be appealing.

when you account for the horsepower of an 8500gt and factor in the scaling of SLI, i would not consider it a good investment. jay2tall gave some good advice in looking for a more powerful single card solution, especially since your resolution isnt really that high anyways.

It will not be the 8500GT. I am trying to decide between the EVGA P55 LE and P55 SLI motherboard. The card I get will be at least a gtx 260. I don't plan on upgrading monitors any time soon.

So you are debating on a motherboard that does or doesn't support SLI, is that correct? The option is nice, but I have only attempted dual cards once, it was crossfire w/ (2) 4870's, and I had huge heat issues. I don't believe I will try dual cards again. I sold them both and got a single 5870. There are alot of benefits to running (2) cards, especially if a 2nd card is relatively cheap. (2) GTX 260's run REALLY well. But you will still have to deal with the heat issues if there are any. If you have the extra cash for the SLI board, I'd say it's worth it just in case you want to venture down that path later. How often do you really replace your motherboard? I usually keep my core system, mobo, cpu, mem, for about 3 years before upgrading. That system usually sees a new video card each year, and I never know what it will be the next time. So the option is nice.

Yes, debating on the non-sli board versus the sli board. Since I didn't plan on getting a new monitor any time soon, I was just wondering if SLI would benefit me enough to warrant taking that route. I agree that having that option down the road would be nice, but I'm thinking around the time I would go for larger monitor, the motherboard would be outdated anyway.

I've had a 22" lcd (1680x1050) for 3 years and it has seen 4 different video cards just to keep up at that resolution with current games. So think about it in that aspect. I am looking at a new display now for my viewing pleasure. I want something larger and brighter.

Righto. If I stay at 1680x1050, is there a large enough benefit to go SLI, or should I save the money and skip it? I'm really looking for either a "There won't be that much of a difference, so its purely preferential." or "It will make a big enough difference, so if you have the money, do it."

With GTX260, HD4870 or higher rated cards there is no reason (except benchmarking) to set up SLI or Crossfire for 1680 x 1050 resolution.

Thank you. That was the kind of answer I was looking for.