MacRumors have done a significant amount of detective work, and tracked down that Apple purchased the website islate.com in 2007, through the registrar MarkMonitor. The majority of the time, this remained secret, but Apple was briefly exposed as the true owners, and MacRumors tracked down the records from that point.
The question now, is if this is the name for the long rumored Apple tablet. As 9 to 5 Mac points out, this was registered at the same point as Apple was fighting with Cisco over the iPhone trademark, which they think means it might have been a backup name for the iPhone if they hadn’t won the suit. On the other hand, Apple may just have been registering i(noun) websites in order to hedge their bets on future products. I guess we’ll see in January.