Jim,
Yes there is software out there, mainly because A/UX has System 7 running on it. I have Word 5.1a, Theorist 1.0, Mosaic and MacDraw 1.0 installed and all run great. You could think of it as a super stable version of System 7 if you didn't use any of the unix stuff. There is even a free version of Eudora mail server and a web server app called httpd4Mac (if you didn't want to deal with Apache)that should be able to run on it if you wanted it to do some server duty. Both are easy to use (and free) and you don't need to play with the unix stuff to much (actually these should work nicely on almost any 7.x Mac). I'll see if I can find my copies of them and check if they work on A/UX.
Important thing to note is that it has two systems folders, one to boot the system and then start A/UX, and a second designed to run on top of A/UX after it is started. If you are going to change anything (add extensions or put aliases in the Apple Menu) make sure you are using the correct system folder or you won't see the changes.
Admiral,
You can actually pull the 68LC040 out and replace it with a 68040 (not a job for the faint at heart). The two are the same, only Motorola turned off the FPU for the "LC" version so they could charge less and to cut down on the overall heat it produced.
As for networking, didn't I see a Newton commercial that had people sending info back and forth across a board room table on a couple Newtons? I still have to spend some more time with the one you gave me, but it really seems like the sky is the limit with it. I'm completely impressed.