I can't comment on Australia (where the article was written) but having worked in the USA and Europe I can say for certain that it's more of a cultural difference and that Blackberries, etc. are just another tool to enhance those differences. I'll explain a bit further.
It's very bizarre, that a the EU which is far more socialist, has a more capitalistic (in the true sense of the word not the warped media definition) than the USA does. In Europe, everyone works with a contract of employment (just like the contracts used in business every day) which state that the employee, will work X hours for Y dollars per hour/week/year and receive Z days vacation. Because it's a legally binding contract the employee doesn't expect an extra $1,000 dollars to magically appear in his pay packet at the end of the month, and the employer doesn't (by EU law) expect or force anyone to put in an extra 20/30/40 hours of work each week, if they choose to, then great, it's their choice, but they have to let the employer know.
On the contrary in the USA there are "At Will Employment" which dictates that the person has no guidelines as to how many hours to work, and in order to get ahead in your job often means that you have to work harder than your peers, often meaning you have to take work home, and work an extra "N" hours a week in order to get noticed, once you set that standard and everyone is doing the same, you open the door to a situation where anyone that doesn't do so, can potentially be disciplined. Because there is no black and white contract to guide either side, it's down to who has the biggest cahonies, the employee to say screw you, my family comes first or the employer to say you're not pulling your weight, get out of here.
So, using that assumption, many Europeans have Blackberry's and other mobile devices, and have for sometime, as to whether the they get used in anger during downtime or family time is more about whether the employee has a "capitalist contract" clearly defining what either side is able to do, or whether they have an at will employer of which they live in fear of, because they can't afford to lose their job/healthcare/pension/dental, etc.
Anyone who's in a position where taking vacation (or genuine sick days) may mean that they get passed over for a promotion/raise/job is bound to blur the work/life boundaries, the tools with which you make that blur happen are inconsequential, mobile computing simply made it easier to do so for those that were already doing it. Just my 52 cents
