Can't work who Moto think the market for this is.....
The lapdock is £300 so it's not a casual purchase or one for anyone that's price sensitive. Most owners change their phone inside 2 years and I see no commitment from Motorola that this is an Apple dock type 'standard' yet that will work with all their phones (or even just an ongoing product line) so there's a high risk you have a £300 paperweight in 2 year's time*.
If you're NOT price sensitive then you'd just buy a Macbook Air - a fully functional computer that's actually *lighter* than the MotoDock and has a better battery life as well. Either way you need a tethering connection and your documents are presumably in the cloud anyway.
If you *are* price sensitive you'd buy either a netbook (£300 buys a decent enough Dell or Toshiba) or spend a bit £100 more and get an iPad. No bigger or heavier than the MotoDock
and give a decent battery life. Neither will be a worthless paperweight when you change your phone.
Moto can give the thing away, which might make you choose this phone over another, but surely that just cuts into their already slim margins in the Android phone market. Even if they did give me one for free how often am I actually going to choose to carry it over a proper laptop or fondleslab?
It's really no different to the old folding Targus keyboards for the Palm. Nice idea but rarely actually useful and redundant and worthless when the next gen Palm launched.