We also have hardwood. It is sealed with one of the more expensive sealers, but it works wonderfully. It was more expensive to install initially, but the long term upkeep is cheaper.
After 10 years, we had them sanded down and refinished. They replaced a few boards that had worn a bit more than the rest of the floor and filled a couple of deeper scratches. Then they stained and resealed. They looked gorgeous again, and the cost, even with repairs was much, much cheaper than having to replace the floor with tile, vinyl or something else.
Also, we have boisterous kids who often "forget" to clean up spills, lots of friends going in and out, a sliding glass door opening right onto the wood floor (so lots of junk tracked in), and two very, very large (120 lb +) dogs with huge nails, of which I am not the most timely in keeping trimmed. And our floors still have held up well. They are not model home glossy as we have a matte finish (easier to care for I think), but still look good as new.
Also, there are now new products you can use to temporarily re-seal sealed hardwood floors. We use the Bona products. There is a polyurethane that you can put on every three months that protects and refreshes the finish on the floor.
http://www.hardwood-cleaner-resources.com/proddetail.asp?prod=Bona-Hardwood-Refresher
I use it religiously every three months and my floors always look like we have just had them sanded and refinished. For a matte finish, we get a pretty shiny look with the product.