It isn't a computer replacement, the formfactor already limits the uses and so I like the limited software.
However, the Palm homebrew comunity has X running on webOS so if you want, you can have "real" apps.
I think you naysayers really need to try it, even if it isn't for everyone, it is going to be a great class of device for lots of people.
I use Nagios and some custom rolled scripts myself.
For some other options, Nagios has now been forked, so if that is "close" to what you want, you may want to contribute to Icinga.
Reconnoiter also looked pretty kewl, but they haven't released anything yet, but it looks like they are planning it to be very scalable.
Never test for an error condition you don't know how to handle. -- Steinbach