I'm on the fence about the seasonal flu shot, to be perfectly honest. There is very little of it circulating, but it's early in the season and the old strains might come back with a vengeance.
Historically, when a pandemic strain emerges, it replaces the previously circulating strains, which then become extinct. The exception to that was in 1977, when an H1N1 showed up, and did NOT replace the previously circulating H3N2. Both H1N1 (human, not swine) and H3N2 have been present since. Prior to that, only one strain circulated at a time, for as long as we have records, so it's reasonable to expect the seasonal strains to die out. But it's just too early to know what's going to happen.
One sure benefit of getting the seasonal vaccine is that it will protect from Influenza B (which will continue to circulate), while the new H1N1 vaccine won't.
I would recommend it for elderly people, since they are more at risk from the seasonal flu than swine flu, and for other high risk groups.
One option would be to wait and see if seasonal influenza rates begin to increase. If they do, there ought to be plenty of vaccine available. If they don't, you probably don't need it. I think this is what we'll do. You can keep your eye on trends here.
There is a long post about this at Effect Measure, if you are interested.