Pretty sure its the elderly that have the most to worry about the flu...
You're half right. The seasonal flu is the one Seniors have to be wary of. Statistically, H1N1, which is a different strain is seeking out the 25 and under crowd. Some in the know feel it's because of the immunity in those that were around the last time Swine circulated back in the 70's
Neither is terribly severe except for those with the underlying conditions the CDC has identified.
There is one bit of detail the CDC has not communicated very well and that is the mortality rate for H1N1 and pregnant women. The rate is almost 30%, extremely high. If you know gals that are pregnant and SEEM to have flu symptoms, encourage her to see a doc at pronto. This sucker is killing pregnant women that have no other underlying condition.