I picked up the slim today and I just wanted to give a couple impressions on it so far.
The first thing you notice when you take it out of the box is how small it is, and how light. The actual body feels significantly lighter, and the power brick does too. The glossy finish looks like its gonna smudge and gather dust extremely easily, especially since I'm sitting it on its side. The really annoying thing here that I noticed is that is came with just a standard component cable, without the HDMI component option. Apparently this is how a lot of people got their Xbox's, but mine came with one for some reason, so who knows. Anyway this means I'm probably going to end up springing for an expensive HDMI cable, which I'm not going to be able to afford until friday, which is a travesty for my 42 inch flatscreen.
A really cool thing is that when you turn it on, the actual power and disc open places aren't really buttons, they're like touch activated. and they start really easily, extremely sensitive. And the machine really does run incredibly quietly, could only barely hear it when I held my ear up close. Also there was a light touch but when you sync a controller to it you only have to press the controller sync button, the xbox just picks up the signal.
Beyond that its pretty much a 360, so hey, kinda cool. If it turns out to have trouble with red ringing issues I'm probably gonna cry a bit.