Canon offers a loyalty upgrade program -- but you can only get the details by phoning Canon support. But if you plan to replace your camera, you may want to call and inquire about the program because it usually offers substantial discounts on some of the models.
The "Rebel" line is Canon's consumer entry-point into DSLR bodies. Canon tends to introduce a new Rebel body "roughly* every year. The T5i is the latest and best of the Rebel line (they also still offer the T3i and there is a T3 (without the "i" suffix) which is intended to be their most affordable body in the lineup. There are mid-level and pro-level bodies above these models.
Any Canon EF or EF-S lens you might own would also work on any of today's Rebel bodies.
Tim Campbell
5D III, 5D IV, 60Da
