Karel has just posted a hint that iRex is planning to deliver a new model of the iLiad in Q2 2007, apparently with extended power:
http://forum.irexnet.com/viewtopic.php?p=4615#4615
There's also mention of a new battery for the original iLiad.
Edit: No, I don't think it will ship in Q2 either, I'm just reporting what he said.