Do we really need another OS?

The second thing that occurred to me today when I read about Google's new Chrome operating system was, do we really need another OS?
ZDNet Australia's news editor Renai Lemay had a similar thought. Renai knows more about Linux than I and about Unbuntu in particular (although I was responsible for IBM's Linux PR in Australia for three years from 2001).
I arrived at the same question as Renai for a different reason.
One of the smartest people I met during my time at IBM was Kevin McIsaac, an analyst who was then with Meta (now part of Gartner). Kevin's view was the number of different operating systems in a organisation's IT infrastructure was one the largest causes of complexity and inefficiency.
Which brings me back to Chrome. Google may be able to build some genuine innovation into its new Chrome OS. But will it be innovative enough to justify the additional complexity that is inherent in another OS?
There saying that if you're going to build a better mouse trap it needs to be not just a little better than the current one but 1000 times better to make it worthwhile for people to switch.
We'll have to wait until 2010 to see if Chrome OS can deliver.