I like the look and idea of an 8bit style pixelated AO, I think if you where going to do it though, instead of taking the game images and just pixelating them, choose the four of the most prominent shades of colour and make the image in a series of thresholds first, and then pixelate for effect.
Either that, or work on very small paint/photoshop files with the anti aliasing turned off
![Smile](images/smilies/d_smile.gif)
That way the colours don't blend together at the edges, preserving your 8bit look.
Take a look at some screenshots from older 8bit games for some inspiration, im sure you will find it.