I don't see how they can make it any "lite-er" than it already is. The original DS was quite bulky, much in need of a slimmer revision, which made the DS Lite something to expect, and the DSi was made to add additional features, like DSiWare, cameras, etc. Nintendo has pretty much filled the 3DS to the max in terms of hardware, and anything about the software that they might want to add can be done through a system update, so there's no need for a DSi-like revision, either. A larger 3DS, like the DSi XL, also is unlikely, because that goes against one of the main points Nintendo is pushing with the 3DS; portability, more specifically, bringing your 3DS everywhere you go, to take advantage of StreetPass, earn Play Coins, etc. Having a larger 3DS would kill that portability, because not many people are going to want to carry something that big around with them all the time. Plus, because it's unlikely that they'd change the resolution, the pixels would just be bigger, like on the DSi XL, which probably wouldn't work well with the parallax barrier.