Health authorities in Australia, as elsewhere in the world are currently obsessed with Swine Flu, or as those same authorities would prefer us to refer to it, H1N1.
The designers at Giant Microbes have even put out a Swine flu soft toy (see here), which like all their other toys are a great likeness of the actual microbes they are modeled from. As usual if you buy one though this link the 10% commission I get goes towards the AEReS project (described here).
Swine Flu
The flu virus has evolved to infect a large variety of organisms, virtually all mammals have a form of the flu and even some cold blooded animals. The ability of a virus to infect its host cell depends on an interaction between the virus and the target cell. Often there are very specific receptor or cell surface molecules expressed on the surface of the target cell that the virus binds to in order to recognize and begin the process of infecting the cell. Since each species has a different set of cell surface proteins on its cells a virus that is capable of infecting one species is not necessarily capable of infecting another species. Occasionally though a virus from one species will either mutate such that it is capable of recognizing cell surface proteins in a different species, or the cell surface proteins it recognizes in its host species is similar enough to the equivalent protein in another species that the virus can cross infect.
H1N1 is a form of flu that originated in pigs but adapted to be able to infect humans (eg http://content.nejm.org/cgi/content/full/NEJMoa0903810), hence its common name of swine flu. There is a good discussion of the current swine flu epidemic at the ABC radio web site (http://www.abc.net.au/news/stories/2009/04/27/2553633.htm) including the point that there is actually a flu variant, the H3N2 variant that passed from humans into pigs.
I have not seen anything to suggest that this flu is any worse than any other sort of flu, and it is not clear why it has caught the public imagination to the degree that it has.