Of course WIFI isn't available in every location, but having travelled rather extensively (including places most probably haven't heard of) I can't remember a place - large or small - where WIFI wasn't available somewhere. One just has to look or ask around.

But the lack of comprehensive global WIFI coverage is beyond the point.You have your mobile phone and you tether. When travelling abroad get a local SIM card and you're always online.

And anyway the key advantages of a mobile companion device are that you can leave it at home, car or in your hotel room, with family or friends, and it still provides service while you carry your mobile around, battery life unaffected. (If both Nokia devices used the same battery model you could just bring one spare... Another incentive to buy a Nokia phone. But why oh why are the batteries always different)

With proper multi-user (incl. guest user) and security features (they're there and open source, it's just of matter of implementing them) you could even momentarily leave the tablet with the friends you just made on the road. You wouldn't do that with your personal mobile phone.

If the Maemo ecosystem fails to gain adequate momentum vs. competing systems, some of us will have an inkling why. (looks at Nokia's market segmentation strategy)