Here's what I understand, you can use the MM dock and webtop dock without the tethering portion but to access webtop mode in either dock then you will have to be connected to wifi. IMO that is just fine with me for now, if i get either accessory I would primarily just use it at home on wifi anyway just to have a second laptop/tablet solution.
Based on the fine print of the press release, it appears that it's linked to the use of the FireFox browser in the linux shell, not the use of the lapdock or multimedia dock themselves. So, does that mean, if we get the lapdock and then full screen android browser or Dolphin browser, that's OK and doesn't require a tethering plan? That seems dumb. Something's missing from this puzzle.
You kinda miss out on the whole portability part of it going that route.