The computer is "outdated" in the sense that better technology is available before you ever get your new computer out of the box. New technology is developed and implemented all of the time.
I would say that a computer (such as the one in my siggie) becomes obsolete somewhere around 5-7 years.
But I love older computers. If you perform routine maintenance on your machine, there's no limit on how long it will last. Of course, just like automobiles, parts can and do wear out and you'll have to replace them, and at some point it's no longer feasible to replace/repair parts because it costs more to fix than the computer is worth. I would venture to say that this happens somewhere around the 7-10 years mark.
It all depends on what you want to use the machine for. I like the specs on the Samsung you've posted. I prefer AMD over Intel, and you might want something with better graphics capabilities. I would definitely shop around before you settle on this one. I've always been a fan of HP computers myself. Excellent customer support/resources. If you want to post more potential buys, many users here will be happy to compare them for you.
But, in short, the computer you have linked to should be fine for an economics major who wants to play games with average requirements...