Coming from a Kotaku interview with Reggie Fils-Aime...
"So we’ve got nothing to announce here. We’ve certainly taken note of all of the readers and consumers that expressed desire for the base model. We analyzed the results in Japan and saw the lion’s share of the volume was on the XL model, and that’s with no 2DS existing in the Japanese market. And so as we thought about what’s the best line-up for us we thought the new XL and 2DS would be our best line-up. Not going to make any promises but, you know, I would suggest to your readers that they stay tuned and maybe some special SKUs might show up.”
It also seems that some eShop exclusive titles on the way that will be New 3DS/XL only.
“There are digital games coming out that are specific to New Nintendo 3DS.”