I'm not all that big on the idea of having one electronic tool that does it all. In my experience this often leads to a tool that optimizes its primary function at the expense of secondary functions[*].
For example, making a single device that would combine the functions of a cell phone and a PDA sounds like a good idea. But most of the attempts I've seen have ended up either being a cell phone with limited PDA capabilities (appointment books that you access using the phone keypad and some menus) or PDAs with a microphone and transmitter. The former are just plain difficult to use, even with technology that allows for quicker entry of words, and the later make for uncomfortable to hold phones. (As an exercise, hold your PDA up to your ear like a phone and see the potential issue).
We are getting better. My employer's (Motorola's) new A630 looks like a decent compromise (see their information sheet) by hiding a small QWERTY keyboard inside a sideways opening candybar phone.
But, I'm not sure I'm ready to give up on the flexibility of separate devices. This leads me to what I'd like to see my employer and their competitors and the manufactures of PDAs (palmOne etc.) do: utilize blue-tooth technology to allow a PDA to communicate with the Internet using the capabilities of a nearby cell phone.
Specifically what I want for Christmas, but cannot get, is a new PalmOS PDA with blue-tooth so it can connect to my new blue-tooth enabled iDen phone (I'm not up to changing carriers right now) allowing me to access Internet sites from the PDA without loosing any of the form or functionality of either of my existing devices (a Motorola i730 phone, and a 3-or-so year old Handspring Visor platinum).
For now, I'll just have to live with what I've got.
[*] In the mid-1980's I coined a definition for "Integrated Software Package" that only recently quit being appropriate, but still applies to a lesser degree to integrated electronic devices: "An integrated software package is a software package that does many different functions, all poorly."