The HD 6950 1GB is an important model for the simple fact that it attacks the price point that NVIDIA attacked head on with the GTX 560 Ti, which really made the HD 6950 2GB just too expensive. Yes, it carried with it more memory, and yes, it performs better in some areas, but with both cards quite neck and neck you would've probably been better off opting for the GTX 560 Ti as it was cheaper, unless of course you wanted Eyefinity.
The HD 6950 1GB prevents AMD from having to drop the price on the 2GB model while offering similar performance. Really, when it all comes down to it, the difference between 1GB and 2GB is debatable.
Unlike the GTX 560 Ti, though, AMD has the option for a 2GB card and while some will argue it's not worth the money, you're not going to change people's minds that want the extra memory and are happy to pay for it.
What the model also does, though, is make the decision harder when it comes to deciding what you buy. The HD 6950 2GB carried with it a good chunk higher price tag when compared to the GTX 560 Ti. If money was the most important factor you would opt for the 1GB GTX 560 Ti. Now, though, you've got this 1GB model that carries an aggressive price tag and the same high performance.
Outside of the actual model on a whole there's the Sapphire version which carries with it a great cooler and an even greater bundle. The inclusion of the mini-DP to DP adapter is great as we're seeing a lot of companies ignore the inclusion of one and as people are starting to make use of DisplayPort monitors it is frustrating to get a card and then not be able to use it until you've got yourself an adapter, which can still be a little hard to buy.
At the end of it all, though, this is a great card and one much needed by AMD and its partners. It offers strong performance and a strong price. From a psychological perspective as well, people feel they're getting a higher end card with this as you're part of the top series - the HD 6900 in this case. The GTX 560 Ti on the other hand is known as a midrange card due to the GTX 460 being a midrange one. Perception is important and it's probably something that's playing for AMD in this instance.
I wouldn't be surprised if we see NVIDIA play a little more with the naming scheme in the near future now that the "Ti" tag has shown up.