If you want or NEED a Terminal application on your PDA, there ARE some for ANY PDA, probably. At least there are for Palm, Nokia, PocketPC devices I know of.
No, there is a dial up terminal application for the palm. There is not however a Terminal.app type device that runs bash or some other shell. None that I could find anyways.(And I've searched and asked alot, and always received the same answer)
For your other points. You are correct about the PIM issue. Although, the Zaurus does have good PIM software and has the same syncing capabilities as a Palm on a PC, it does not yet sync with MacOSX, unless you use X.
But then again, the Zaurus is not billed as a PDA but as a PMT(personal mobility tool). And the one problem with your PIM argument, that is also begining to chip away at Palms hold on the market and eventually will kill Palm unless they get their act together, is that people are turning away from traditional PDA's and looking more for items that do more of #2 than #1(PIM). For example:
People like the idea of wireless, and, unless you buy a m705, you are going to spend up to $350 more to convert your palm into a wireless device.(Oh yeah, I guess you could buy an old PalmVII) But my m505 would have cost about $350 to turn into a wireless device. No thanks.
I like to be able to look at a problem, pull out my device(that sounded bad), and begin working on the solution without having to trudge back to my mac in my office or write everything down on a tablet and then transpose to my mac, etc...
So can I do without the "no brainer" syncing of my PIMs? Sure, for right now. Besides, if I wanted the data on my Computer, what do I need a PDA for? Easy access to phone numbers? Don't need a computer for that, got my Zaurus. Easy access to my appointments? Don't need a computer for that, got my Zaurus. Easy access to my software writing programs? Can't do it on my Palm, don't need my computer, got my Zaurus.
So like I said before. If you want a PDA that keeps track of Phone numbers and appointments, get a Palm, their cheap and very eeficient at this. If you want something a little more get a Zaurus.
Good Luck.
SA