I agree with Servant, though it isn't exactly pixel art though. The reason is mostly because you have to do things too big to get nice results, and the style ends up being far from pixel art. I guess if you "Cubify" the model first, you may get an interesting style, but I doubt it will really look like pixel art honestly, though I see where it could happen.

I can't sprite worth squat. The game I'm working on will have graphics all based on Blender. I recommend you maybe have a single file. On layer 1, put your light setup and camera, and whatever object you are working on(or rendering at the moment). For lighting, I recommend you mimic pixel art lighting, which in many cases is directional from the upper right to the lower left. Also, I use AA, with Catmull-Rom Filter at 5 levels. Make sure under "shading" in the "Scene" properties you set the alpha to transparent(as opposed to sky), and I would use PNG files with RGBA channels. This method gets you a nice clean edge.

This method of sprite creation is great, assuming you are doing 64x64 sprites and up. If you go lower than that, you lose too much detail in my opinion.

In my current project, I'm using the above techniques. The models are generally simply colored, not high saturation, and using Blender integrated textures, like Clouds, etc... to create surfaces. It works pretty well for the most part. A real artist could get much better, using pixel art or 3d renders, but this way the result for me is still much better than what MY pixel art would be. I should also say that you can get different styles using Blender's renders. You can get edges rendered if you need to. You can change lighting models to get sharp highlights. You can also use a technique I've seen, which I found I think on Blender Cookie. Google "Blender 16-bit sprites" and I think you'll find it. It involves changing the lighting model to use a texture like a cloud texture, which ends up creating a sort of "dithering" instead of smooth highlights. It can be an interesting style. The reason I'm not currently using it is that due to the material settings, you can't easily animate the actual colors of the materials easily.

Which leads me to mention the following. In recent Blender versions(2.5 and up), you can animate almost anything. This includes material colors, specular brightness, any material settings almost, including generated texture settings, like cloud size, etc... I would use this for you advantage. For example, my reactors in my game are bright blue in the middle, and a semi-shiny metal in the dome and base. When they get hit(destroyed), they compress down to where the dome and base are together. To make things look better, I've also made the middle part no longer shine during this animation. Also, the dome and base metal colors are much darker(duller). If I really want to, I could possibly add a texture or two, for like "cracks or scratches" and then set the material to not affect anything, and then show up during the animation. In fact, i think I'll do that tomorrow evening after work. Also, you seem to know the good use of re-using animations. This is great in that if you need to re-render something, you only change what you need, and you don't have to re-draw everything like pixel art.

If you really want some examples of my game's art, I can post them to my dropbox. There isn't much yet, but I'd show it if you want me to.