To answer Tim's question from a rather useless UK perspective, the oil is not yet on the Mobil website and when I e-mailed them with a query on stock availability in the UK they did not reply.
However, on a related point I took my Insight to a Honda dealership (for the first service since I have owned it) for its 18,000 mile service. I specifically mentioned 0W-20 oil to the service manager before the service and he assured me that they would put the right oil in.
£170 later ($267) for literally an oil change and a checkover and I found on the invoice that they have put 'Mobil Super S' in my Insight. After checking the Internet when I got home I am reasonably sure that this is a 5W-40 oil. Should I be concerned?