I've just bought this Canon 550D with the 18-135 IS lens and have so far been very impressed. It handles low light shooting very well, as a result of the IS facility and very high ISO ability.
The range coverage of this lens is excellent, from landscapes to close ups and the images I've got so far are very sharp and detailed. It can shoot in RAW mode along side high quality JPEG, so you have an image ready to show (JPEG) and an image you can tinker about with (RAW) on your computer until it is perfect (the provided Canon software makes it very easy to do). Navigating around the camera menu becomes a breezes after a few practices, although keep the manual nearby as there is a wealth of information to digest from it. The screen on the back is fantastic and crystal clear. The camera feels comfortable to hold (even in my big paws!) and is not to heavy to cart around. The microphone port is also a welcome new addition as it will allow you to capture the sound in stereo and enables you to choose your microphone weapon of your choice rather than being condemned into using the built in microphone (which does the job).
The only moan about this kit is that the AF is bit noisey, as it's not a USM lens, but if you want a comparable zoom range in a Canon USM lens you'd be paying a hell of lot more money (eg the 15-85 IS USM).
A couple of tips before I go
1) Buy a decent SDHC card like a Sandisk Extreme with a class 10 rating, preferably 16GB or more (for the video capture side of things especially). Don't be lured into buying a cheap card because it has a high capacity as it won't read and write the data fast enough to
be of any good, especially the HD video. Canon recommend at least a class 6 card.
2) Get a powerful computer. I am going to upgrade my desktop PC (or get something else). It has a 3.4Ghz AMD processor (albeit 5 years old), 1GB RAM and 256MB graphics, running with Windows XP. It can't seem to handle displaying the captured HD video and is slightly slow in processing the RAW images (each of which can be around 24MB in file size).
Overall a top piece of kit that you won't be disappointed with.