The latest I can find on the release date was a board post a half year ago: http://www.grimrock.net/forum/viewtopic.php?f=3&t=2796
There are a bunch of games I want to buy an iPad for but this is the one I'm waiting for to finally buy one. So addicted to the PC version but I'd love to be able to take it on the go with a touch screen. With all the silence on an iOS version I've almost broke down and bought an All-in-one PC since the game has a tablet mode in the options now.
The silence is kind of off-putting since iOS was the first OS Grimrock was officially announced for - even before the PC version. Have they silently cancelled it? We've not seen or heard anything since those first alpha screens of the iOS version.