Sony shouldn't leave the handheld market. Let's not Sony is generating a profitable. You don't stop supporting a product when it's making you a profit.
The biggest problem the Go has is it's price. My little "reboot" strategy was to help to repair any damages to the image of the device, but they could obviously make a Kevin Butler ad with a lower price point will do wonders for it, without my other mentioned stuff.
I did however forget to add that Sony should do a marketing campaign similar to the "It Only Does Everything" campaign. I just forgot to put in my first post.