One thing that's really helpful about the Palm as a PIM is that it can synchronize with desktop based systems, or more to the point, server based systems. In particular, I can sync my calendar with a couple of different server-based calendar apps, so the rest of my work group can see when I'm busy, and I have an up-to-date copy of my work calendar with me when I'm at the dentist making my next appointment, etc.
I'm not sure the iLiad would ever replace my Palm for the latter purpose, but it would be nice if it could also synchronize so I could have my calendar and other info on it. I haven't looked at open-source Linux apps to see if there's one that does this. My employer uses outlook for calendering, so that's what I'd need to sync with.