This is my first dslr; I stepped up from the canon sd750. I am so happy with the xsi. All the manual features and customizations are great for the intermediate/advanced photographer.
For those familiar with CHDK for canon cameras, I've added that to my sd750. Even with the unlockable manual features with CHDK, a solid dslr blows a point-and-shoot away. The image quality is so much better.
The fact that it is an dslr, changing lens is wonderful. I bought an olympus om to canon eos adapter on ebay to use my old olympus lens on the xsi. Unfortunately, I haven't received the adapter yet, but the customization options are limitless. An external flash is also a great and vital add-on.
Overall, I'd recommend this camera to anyone who is looking to step up from a point-and-shoot camera. Get more detail about Canon Digital Rebel XSi 12.2 MP Digital SLR Camera with EF-S 18-55mm f/3.5-5.6 IS Lens (Black).