I'd buy this in a heartbeat...but wait..I actually like using the internet. As in enjoying youtube, skype facebook etc and uh oh Econet, with your pricing thats clearly an impossibility.
So I don't see this thing gettting widely adopted and to the few that buy it , there will be bickering aplenty in their households as all it'll take is for one person to connect their laptop and those pesky windows/eset/firefox updates to promptly drain the expensive megabytes. And no not everyone is going to turn off all those automatic updates as unfortunately, econet, we all can't be data saving geeks. Maybe these device should come with fixed/semi fixed (eg zol wimax) tarriffs? I dont care if my connection can reach 21mbs. All I want is 1mbps affordable connection that allows me to use the internet without the thought of how many megabytes I've used.
So for the meantime I think people will still be happy with Africom or Powertel (both seemingly dependant on location for good speeds) and the lucky few will keep their yo-africa packages which actually offer 2mb/s off peak as long as you behave during on peak hours and stay within your monthly gig.