Canon have updated the 550D to the 600D (also known as the T3i) - and it seems to be a relatively minor incremental upgrade rather than any new breakthroughs, taking a few features from its elder sisters, the 60D and 7D:
- Swivel LCD screen
- Ability to remotely control flashes
- A 'feature guide' to help you make the most of the camera (hmmm)
- iFCL metering
- A new 'Movie Digital Zoom' 3x or 10x crop, retaining full HD (obviously something's got to give though...)
There's also a slightly tweaked version of the standard zoom kit lens, now known as the 18-55mm F3.5-5.6 IS II
I got a bit bored (i.e. underwhelmed) reading the rest of the press release, so there's more information here.