Digital technology changes very quickly, becoming both better and cheaper.
Digital cameras made 10 years ago are now nearly forgotten. Those made five years ago are obsolete or nearly obsolete.
The Pentax K-x, a DSLR introduced two years ago, is not only no longer made, but camera advancements have robbed it of it's charm. What made that camera unique two years ago was that one could not find a better sensor and software combination for that price--not even close, really. Now, with the Sony NEX-7 and soon-to-come Canon G1-X (which have superior image quality for not too much more money), as well as advancements in digital point-and-shoot cameras (which have superior prices for not too much less image quality), there are not many reasons left to choose the K-x.
That's in a matter of two years.
Two years from now, the NEX-7 and G1-X will lose their charm to further digital advancements.
It's difficult and expensive to keep up with all the changes.
But here is something camera manufacturers do not want you to know: any camera can be used to create great photos, any camera. It doesn't matter what make or model your camera is, or how new or old. If you know how to create great images, you can do so no matter what camera you have. And if you don't know how to create great images, it doesn't matter what camera you have because you still won't take great photographs.
So, while it is nice to get new equipment, if you can't afford it right now, don't fret! Whatever your camera is, it will do just fine.
And that nice, new camera won't be nice and new for long, because digital technology changes quickly.