It doesn't run on 10.5.8, so I'm holding this review until after I upgrade to 10.6.
It didn't work on 10.6.8 either, just coming up with a "Loading" screen that hangs their seemingly forever. I'm on an early 2008 MacBook, certainly not the fastest computer in the world, but one that is usually adequate to the task of running most software.
After prompt help from Bluestacks tech support, I tried again, this time first closing my Chrome browser windows before starting. Lo and behold, it fired up promptly. The diagnosis was "not enough memory", and sure enough once I turned off my browser there was enough memory left to get it to start.
From all I could tell of using the system with one app loaded (Twitter), it was a faithful emulation of the Android environment. There's an app store or two so that you can get new stuff. But once I started to load more than one app at a time, the system started to bog down again, and the output from "top" showed a load average of 7+ and no free system memory.
I'm willing concede that it might work on some computers, but it's not working well enough on mine to be anything but a curiousity. It certainly can't run on this system at the same time as my browser. There is hope that a future release will be more sparing of memory, in which case I'll give it another try.
More information: http://bluestacks.com .