I see nothing wrong with keeping email, IM, Facebook and whatever else separate from my phone number. Despite the conventional wisdom of this age, I have no desire to be "constantly connected" and reachable, much less have it all rolled into one convenient number. Besides the "one stop" hacking opportunity alluded to in someone else's comment above, it also strikes me as one more step towards a world of constant surveillance.

I have written a satirical letter to the Aussie senator in question, and have now posted it on my blog. Feel free to take a look: www.jamesdeagle.blogspot.com