To answer your questions:
Q. Is the Xcode 4 preview suitable for
production work (i.e. releasing
Mac/iOS apps), or should I wait until
a final build is released?
You can develop in Xcode 4, and move back and forth between Xcode 4 and 3 with the same projects. You are meant to use Xcode 3.2 for submissions to the App Store, but it isn't clear whether that is enforced or just that bugs in Xcode 4 could get your app rejected.
Mac apps don't go through the app store, so if it builds and deploys, away you go :) Make sure to test thoroughly on your deployment platform(s) just in case!
I live and die by my console window.
Is that window also integrated in to
the IDE window, or can I have the
console window appear separately?
It's integrated. You can go to the debugger navigator or you can 'show debugger area' from the view menu to have it appear below the other navigator areas
I can't post images, but you can see them at: http://i.imgur.com/8A75R.png and i.imgur.com/hAjqx.png
On the overall questions of stability/practicality: My experience is that the new design is really nice. Things are laid out much more logically. It still slows down the process of coding as you adapt, but I'm digging the new Xcode and think I'll be faster with it overall.
There are bugs, especially if you push the envelope. Using LLDB instead of GDB tends to cause my computer to lock up entirely, for example :(
If you need to be productive and you want to waste the least amount of time getting things into the App Store right now, Xcode 3.2 is where you should be.
If you want to muck around and can afford to spend time learning the new design and features while dealing with crashes, then Xcode 4 is very rewarding. Long-term, it is a big improvement on the current Xcode.
