Nothing is _always_ on-line. Even my DSL line (or someone's cable modem, or my work's multiple T-3's) goes down. There are cellular dead spots and areas outside of cellular coverage, etc.. If I'm in a dead spot, and want to call someone on a landline, it'd be nice to be able to look in my addressbook to do so, but your concept wouldn't allow me to do that. Devices that depend upon being online are "part-time paper wieghts", and I sincerely do not want to _ever_ own such a device. That's not what convergence means to me. Convergence means "brings together the functions of multiple devices", not "becomes braindead because of an over-dependence upon the unreliable features of one of those multiple devices".

Or what if netvouz is down, and I want to find that bookmarked but not quite remembered site? (don't say "use google bookmarks or delicoius" -- folderless/tag-only bookmarking systems suck posterior orifices; but even setting that aside, it IS conceivable that google could go offline, same with delicious) Even if they don't crash, it's nice to know that I have my own copy in case I switch online services, or one goes out of business, etc.

From there, it would be nice to know that all of my addressbooks (and calendars, and to-do lists, and bookmarks) are in sync with each other, so that there aren't confusing conflicts (or omissions) between different pieces of data.

OR.. what if I decide to let my data plan lapse, and just have voice/SMS/MMS for a while and just do wifi for data? It'd be pretty annoying to not have a local copy of my addressbook just because I'm outside of a wifi hotspot.

Even you say "anything stored on it should be easily transferred to the Internet" which says "I need a way to sync the convergence device to some other thing", whether that other device is a desktop or a cloud service. And, what about those cloud services that are inadequate or undesirable to the individual? There is going to be data I want to put on my handheld and not on an online service (non debatable). And I want those files to be backed up, in case the handheld dies.

As for "if I have a keyboard, monitor, and mouse, why wouldn't I have a computer, and why wouldn't I use that instead of my handheld device". Well, for one, if my handheld device is up to the task of processing/storing everything I need for email, IM/SMS/MMS, web browsing, and ssh keys, and things like that, why would I need to offload that to a desktop computer? When I want a bigger/faster _input_ method, what I need is not "a bloated piece of sand, plastic and metal that does a great imitation of a space heater" ... what I need is a bigger screen, a bigger keyboard, and maybe a different pointing device. Why not attach those to the handheld? It's already up to doing that job just fine, it just needs a bigger screen and faster keyboard for a little while. Shutting down the handheld and moving over the desktop is pointless (and has an annoying side effect of leaving around multiple out-of-sync chat logs and multiple devices, for the case of IMs).

That doesn't mean I wont also have a desktop or laptop, for those tasks that really can't be done on the handheld (long term personal/private/sensitive file storage, backing up the handheld, CAD work, rendering, home email server, home media server, etc.). Which is why I mention the KVM (why not re-use the same monitor, keyboard, pointing device that I'm using there already?).