I've just seen an on-line report that some parents overseas have been organising 'swine flu parties' (more than just your average sleepover), deliberately exposing their kids to the virus in the belief that this will give them immunity to a future, more virulent strain. Something like the 'measles/chickenpox parties' which have also received some adverse comments on sites like Orac's.
Those adverse comments apply to swine flu get-togethers as well. This Influenza A (H1N1) virus seems to be reasonably benign, in the sense that most reported cases have involved a mild-medium dose of flu. But even that is unpleasant - why on earth would you deliberately make your kids that unwell? Quite apart from the fact that there will be individuals who develop severe illness, not least those who are immuno-compromised for some reason. (NB measles isn't a trivial disease either, & even chickenpox can be extremely unpleasant for some sufferers.)
And while it doesn't make most people seriously ill, the virus is extremely infectious - one colleague who works in this field confirms that press reports that roughly 30% of the population will get it, are pretty accurate. That's a lot of sick people. And since flu is often accompanied by other, secondary infections that can lead to further visits to the doctor, or in serious cases hospitalisation, it's quite possible that our health system will be overloaded as the illness spreads. Deliberately spreading it by holding these 'parties' is not exactly a smart thing to do in these circumstances - I can only hope that the idea doesn't catch on here.
There's another reason for concern. As ERV has pointed out, different viral strains are more than capable of exchanging genetic material. In fact, Influenza A (H1N1) has already done this at some time in the past, as it seems to contain an amalgam of human, swine, & avian viral DNA. There's a real worry that, if someone with a virulent form of 'seasonal influenza' also picks up swine flu, the latter will add virulence genes to its existing genome. A flu virus combining very high infectivity with high virulence would be a very nasty customer indeed.