I asked Kobo about when they are expecting more stock for the Espresso for their webstore, first I asked via email, before they opened for the day (Friday) I think but after quite a few hours with no reply and seeing someone mention their twitter in another thread, I decided to try it and they seemed to imply they're hoping to have more stock next week
https://twitter.com/KoboHelp/status/330433977578041344