The 3DS still isn't doing that well outside of Japan, so that's not a great example. A better one would be the DS, which was regularly being outsold by the PSP outside of Japan right up until the Lite came out and that's where it took off.
The Vita certainly needs more game announcements but the idea that that's all they need is ridiculous. The Vita already has a good game library, the problem is that there's so much scepticism over its future, over its price and over a variety of other things, that people just write it off.
Sony need to start from scratch and build some momentum and a "re-launch" is the best opportunity to do so. New SKU, price drop, memory card price drop and new game announcements. All four, I think, would be integral parts of it. Get rid of one and it's a flop. So if the OP is right and Sony thinks that they can just release a new SKU and keep the same price, they're absolute idiots and aren't really interested in making it a success.