Ultraportable
Stylus enabled
Fully capable desktop operating system
Ports to allow hook-up to external monitor
I wanted something like this as a frequently traveling and programming, conference hand written note taking engineer. Then I notice some of the designers in my office experimenting with iPads, Pencils, and Mac minis (seeing if they could depend 100% on the iPad for portable work). The main complaint has always been, why didn't they stick osx on this thing?
Devices that have come close, besides the iPad:
Acer Chromebook tab 10: stylus support great, ultraportable, but abysmal battery life and lacking peripherals to turn it into a reasonable laptop alternative. Chromeos though, with Linux Apps on Chrome combined with Android Apps on Chrome, now seems a powerful contender in this niche. USBC. Stylus built in.
Lenovo y500: ticks all boxes but ultraportable - thing is a tank. For now I swap between this and the x1 yoga on trips. Runs chromeos which means I take notes in onenote for Android, and program in a vscode for Debian binary or emacs or vim. Getting localhost to work kosher is tricky. USBC. Stylus built in.
Lenovo x1 yoga: not ultraportable, just a damn good laptop. Unfortunately, there's no good handwritten note taking app (at the level of onenote, anyway) for Linux, so I swap between Ubuntu or windows 10 depending on what I'm doing. Same for photo editing, which is a deficiency I forgot to mention for the chrome books. Usbc. Stylus built in.
Surface pro line: probably actually ticks all the boxes, I just hate programming in windows and haven't touched one of these that are powerful enough to run Ubuntu in a VM in a reasonable fashion. Also, the keyboard is awful imo. And, I don't know if they do USBC yet? That would mean no charging from the backup battery if so. Finally, the stylus isn't built in, which is obnoxious.
I've heard fun things about Linux on Android and other Samsung specific offerings that I'm looking forward to experimenting with. The hunt for this device has become a mild hobby.