As others have mentioned, new models always replace older ones and it's not usually anything to be concerned with, the old model will be perfectly serviceable or they wouldn't have been selling it.
There are also other good reasons to recommend buying a camera once it hits "end of life" and is to be retired from the shelves...
For a start, you can make a more informed purchase as:-
- Any stock you buy will have had any manufacturing kinks worked out.
- Third parties will have real-world data on the performance of their products.
- A large body of user experience with that specific model will be available on sites like this one.
- Any problems that come to light through real-world usage will be well known.
As a case in point, read up on the story of the Nikon D600. A camera which looks great on paper (and is nice to use btw) but some issues that have arisen with dust/oil spots have meant it has been replaced by the D610 in fairly short order.
Finally, it makes sense economically in that you will be paying less for a camera that you'd have been happy to pay full price for only a couple of week/months ago. You're still getting the same equipment, just with a bit of cash left over to put towards other things like a better lens or accessory.