It is slated to be available in April. Here is the announcement:

Canon U.S.A.'s New EOS Rebel XSi Places Superior Optics and Professional Features Into The Hands of Emerging Photo Enthusiasts

Canon 'Beefs Up' the New Rebel With Optically Image Stabilized Lens Kit and 'Pro' Features

LAKE SUCCESS, N.Y., January 23, 2008

Hello--

There is a lot to be said about the new XSi, to be sure. The specs sound very intriguing, and it seems like a much bigger upgrade than the XTi was from the XT.

One of the big strikes against it, however, is the fact that it doesn't come out until April. If you can wait until then, you might consider holding off. However, if you're interested in making photographs right now, you would still be very happy with the XTi. It's a great camera at a great price.

One thing I have to keep reminding myself is the fact that the camera is a tool. It's easy to get wide-eyed about new features, new specs, and new possibilities, but in the end the responsibility of making a good, solid photograph lies with the photographer...not the camera. Will the XSi make better photographs than the XTi as a rule? Not necessarily. It's all about your skill, your choices (aperture, shutter speed, lens choice, composition, etc.), and your drive.

Remember, there will always be the promise of a new "updated" camera just over the horizon. If you buy the XSi, within a year or so you'll be hearing rumors about the "fabulous new Rebel" that will be released "soon."

I'm not saying that you shouldn't consider waiting, but what I am saying is that if you want to make photographs NOW, buy the XTi, enjoy it, and have three months worth of photos on your hard drive before the XSi is even released.