[Galaxy S III Accessories] marcucci217:
This would probably be the best option TBH. I'm not a huge fan of a physical keyboard myself, but I see a lot of people not making the switch from RIM because of the lack of great Android hardware with this (primitive?) feature. I agree with the above poster in regards to the fact that the industry is moving away from physical buttons, in general. Even RIM tried multiple times to "dip their fingers" into touchscreen technology (see BlackBerry Storm or BlackBerry Torch) but (IMO) could not sell enough units to justify abandoning what has been successful for them for nearly the past decade. Of course manufacturers are seeing sales explode as they are producing thinner and thinner phones, simply because phones that have slim, aesthetically-pleasing design profiles are much more desirable for a multitude of reasons. I'm afraid to say that until a manufacturer can produce a device that is competitively thin and light I don't see physical keyboards remaining relevant for much longer.

However, to more directly address the topic of this thread, I don't think that any other "keyboard cases" will be seen for this phone, so you should probably try and request that the company in the quoted post create one. For one, as hinted to above, most people purchasing this device see its sleek profile as a major perk. Many people across multiple forums are discussing which cases are best and are looking for the following desirable attributes: thin with a lot of protection. Some will sacrifice their "1mm or less" requirement for a case that will survive a fall from a pocket or backpack, and these people (sometimes begrudgingly) purchase popular high-protection cases such as the Otterbox Commuter/Defender or Trident Aegis/Kraken. I believe that this is the only reason people would be willing to purchase thicker cases for this phone (or at least enough people for these companies to justify making cases that are purposely thicker). Additionally, these people are paying a premium because the manufacturing costs for making these thicker cases are certainly higher. If just having thicker, more protective materials are driving the costs of these cases above ~$25, how much would you assume the Bluetooth keyboard cases would cost? BoxWave charges $79.99 for their iPhone 4S version at the time of this post - a pretty hefty amount in a market where people are looking to eBay to purchase cases for under $10. It just doesn't make sense economically for companies to produce cases like this.

One might argue this point by using the existence of the BoxWave iPhone 4S model as proof that enough people will buy an expensive, thick case to make it happen for our comparatively slim phone. However, this defense would ignore the main reason why a physical keyboard is more (read: slightly) in demand for Apple's flagship device. When comparing the ease of typing on the iPhone 4S, which has a 3.5 inch screen, to that of the Galaxy S3, which has a 4.8 inch screen, their is no comparison. The larger screen real estate of our phone is vastly superior mainly due to the fact that the key size can be quite a bit larger. Also, one should consider the fact that Android keyboards can be changed quite readily and are becoming much easier to customize. It appears that anyone can find a keyboard that works for them, no matter their virtual typing style. Therefore, I don't imagine the demand being even close to similar.

That is just my two cents. I will request the case for you, but I honestly don't think that it will come to fruition for the aforementioned reasons. People are not looking for heavy, sturdy handsets anymore - they try to keep it simple and light. Keep in mind that Samsung was able to sell 10 million units in record time and the build quality does not even resemble that of stuggling manufacturers like HTC and Motorola.