See Also: Canon DSLR Reviews
When Canon discontinues a camera model, they usually have replaced it with a better, more capable, model. Whether or not that new model is worth the price premium over the discontinued model remains a valid question. Be sure to read the review for the current camera model that most interests you before deciding to buy the discontinued version. If the discontinued model is no longer available in new condition, risk is added to the discontinued side of the purchase equation.
Some of these DSLR cameras were primary in my kit for years. They are fully capable of capturing great images. That said, I would definitely miss some of the later-introduced feature upgrades.