The journalist makes his off-hand but apparently certain statement while discussing the relatively poor state of Internet access in the US, whose cellular and landline connections are often outrun by foreign providers.
Mossberg doesn't cite any sources in his talk with executives, in which he also comments that the Apple TV is limited by the speed of American Internet access.
However, the technology critic is also known for gaining privileged access to information and products from Apple. Mossberg received his review iPhone on June 11th last year -- more than two weeks before the touchscreen cellphone was available to the general public and ahead of most other journalists.
The comments echo the increasingly repeated June timetable for a launch of an iPhone with faster wireless access. In recent days, multiple analysts have predicted that Apple will unveil its 3G iPhone no later than June, with Piper Jaffray claiming that the ongoing iPhone shortage is a sign of inventory control measures meant to phase out older models.
T-Mobile Germany has further sparked interest by subsidizing the price of 8GB iPhones in a promotional campaign that ends June 30th.
Mossberg's statement can be seen in the video below at the 6 minute, 53 second mark.