Yes, revolutions will come and go with or without twitter, but to ignore the massive multiplier effect that viral social media has in situations such as this is ludicrous ... the fact that this is coming from the man who wrote 'The Tipping Point' is especially ironic.
Now, let's remove Twitter and the media completely.
What do we get? So we had a revolution in Tunisia that was very well televised and communicated.
Remove the modern means of communication and media and Egyptians would have no where as much of an idea or source of inspiration, certainly not within days of the Tunisian revolution.
You can always retort that without mediums such as twitter news would still spread even if at a slower pace. And similarly, a revolution would also occur even if at a slower pace.
Then the pace at which a revolution is occurring becomes a major point of contention in this debate. I'd argue that twitter, cell phones etc. have significantly increased pace of communication and thus the time to revolution. To, then, belittle them is like saying who needs cars when we could still WALK 5 miles; it'd just take longer. A lot longer.