Nintendo has recently dropped the price of the DSi (from $149.99 to $99.99) and DSi LL ($169.99 to $129.99), something console developers regularly do before announcing a new model. This added with the fact that Amazon.co.jp (the Japanese Amazon.com) has mysteriously run out of stock of all models of the 3DS simultaneously has led some people to believe that Nintendo may be planning something... Amazon.co.jp are expected to restock all models on June 4th, 1 day before E3.
Of course, the timing of these events may be simple coincidence. The 3DS is still selling strong and with recent color variation releases, Nintendo doesn't have any obvious reasons to release a new model. Still, that has not kept people from voicing their opinions and speculations.
Personally, I hope they hurry up and release a damned "mega battery" model.
Amazonで3DSが全部品切れ状態・6月4日に何かがある！？ [DS PSP初心者講座]