Just a few hours ago, Amaranth pushed a CraftBukkit update for Minecraft 1.4.2. Some bugs have already been found, and a few fixed by this time. Updating CraftBukkit will take some guesswork, but I'll figure it out eventually.
Now, what I did with Minecraft 1.3.1 was write a requirements document, indicating the things I had to do in order for us to update successfully. This was mainly done to keep track of progress, so I could get things done in a tiimely fashion. I've done the same thing for 1.4.2, and like this strategy. Some of the things listed for 1.4.2 might be omitted, as they aren't critical to the internal workings of the server, but we'll see.
Now, it'll take some time for our other plugins to get updated, but I'll be always on the lookout for when those changes have been made. It is my goal to make sure we're ready for 1.4.2 as reliably as possible. That is, so there are no major CraftBukkit bugs. Hopefully we can do this in less than a week. I'm hoping that is possible.
IDP Development Team