Looking at what you're listing and how Nintendo needs to keep the price low ($200 at launch should be their goal), I'd say Nintendo should only adopt some of your suggestions. Getting a gigabyte or three of RAM should be simple enough (many smart phones already have 2 GB), especially for an improved OS, and the Snapdragon-ish CPU would be good. But I really don't think HD is needed for a handheld, especially one with the two smaller screens like the DS and 3DS have. Something near standard definition, maybe 200 pixels per inch instead of the 300+ of smart phones, would be fine.
As for 3D, I think it might be worth keeping, at least to an extent. 3D didn't take off that much, but I'm not sure how much it's adding to the cost of each unit. Maybe there could be two versions of the handheld, one with the 3D and a bit of extra power to manage it for a slightly higher price (bundled with a simple game)?
Love and tolerate.
