Is this the start of a global flu pandemic?

The World Health Organisation says the new H1N1 strain of swine flu spreading from Mexico has "pandemic potential" and has stepped up surveillance, alongside national bodies such as the US Centers for Disease Control. The WHO emergency committee says it does not yet have enough information to step up from the current "level 3" pandemic alert, which was a response to the H5N1 avian flu circulating mainly in Asia. Flu is too unpredictable for anyone to say confidently at this stage what is likely to happen.