Canon's Digital Rebel cameras have always been hard-hitters among entry-level DSLRs, but Canon is poised to sew up the market with its new T1i--a camera that's a clear response to Nikon's D90. Primarily, it's because the T1i not only has the same 15.1 megapixel sensor as its semi-pro Canon EOS 50D cousin, but it can record video in 1080p full HD.
The camera is an evolution of the old XSi, but its new sensor also comes with Canon's newer Digic IV image processor chipset, and the ISO range of the camera's pushed up to 100-3200 with two "extended range" settings that can go up to ISO 12,800. There's a 9-point AF sensor array, and it can shoot at 3.4 frames per second for up to 170 large JPEG images with the right fast memory card inside. And instead of using compact flash, like the cards the 50D uses, the T1i saves to SD or SDHC, which is much cheaper.
But it's the video recording that's the hot item on the T1i--just as it was when it was introduced on the EOS 5D Mark II last year. By recording at 16:9 720p at 30 frames per second, and full HD 1080p at 20 fps, the camera, with its interchangeable lens suite, effectively brings high-level HD video recording capabilities right down to beginner level.
There's also Canon's self-cleaning anti-dust system on the sensor, HDMI-out, and a 3-inch view screen with Live View image previewing so you don't have to rely on the viewfinder.
In fact, there are so many similarities to the company's semi-pro-level 50D camera, that it can only be a matter of time before that unit is upgraded to a 60D, or gets some of the new features--like video recording--via a firmware update (rumors of which  are just surfacing, though there's no word on video yet.) Otherwise Canon will cannibalize sales of the 50D. That's because the new T1i is going on sale with an 18-55 image-stabilized kit lens for just $900: the pre-discount price for the old XSi with the same lens is just $800 , and the full-priced 50D  costs $1,300 for the body only at Amazon.