I've spent a month working from iPad exactly as you suggest. I do work from my desire in exactly that fashion on a fairly regular basis. As to "too cumbersome," why yes...laptops are. Even modern windows tablets are just too bulky and heavy. That's not the killer though. The killer is battery life. Full-fat operating systems just don't have the battery life necessary for me to get a day's work in.
Remember, you can type just fine on an iPad. Which means no need for a keyboard. There doesn’t have to be a habitrail of copper to cool some ridiculously over-the-top x86 chip. You don’t have all the “baggage” of trying to be the everycomputer. It’s just a media consumption device capable of RDP. I’m a sysadmin, and a programmer. I’m a user and a consumer. Shockingly…the form factor works brilliantly for me.
What doesn’t work for me is the locked down nature of the iPad; specifically the inability to use removable storage. I need the ability to carry a few SD cards with my movies/tv shows/songs/whatever. I have laptops. Nice ones too. Since getting my Desire I almost never use them. If I had an iPad-alike I can pretty much guarantee they would gather dust.
I just don’t understand what average tasks require you to have a full fat system at your fingertips? Sure, there are some heavy lifting tasks I would prefer to do at a real workstation: photo/video editing. (Proper colour calibration requires a real monitor and a real video card.) CAD. Video gaming. Those are all activities I would do from one place though; not on the go. I would have to specifically set time aside to do those things, which means finding a desk and parking it.
When it comes to 90% of what I use a computer for…I don’t want to be sitting down at a desk and staring intently at a light screen. I don’t need to be tethered to write a comment on El Reg. I don’t need be tethered to read/write e-mail, consume media, check facts online or enter inventory items into my corporate point of sales system. I don’t need to be sitting down to use instant messenger, Facebook or check on my webcomics.
What 10 years ago I would have done on a low-power desktop or five years ago on a notebook I now find myself doing on my phone. True “workstation” tasks still require a beefy “workstation.” The difference is that “workstation-class computing” lives inside my Alienware laptop and sits unused in the corner until I actually come up with a task that requires it. All my real work is done in my personal VM and delivered over RDP.
With a little bit of effort, a lot of that “workstation computing” can even be moved into a VM, providing even fewer reasons to bust out the power-hog.
Let me be clear: we aren’t yet at the point that regular folks will be ditching their desktops/laptops for iPad-alikes. We are however seeing the start of it. It’s no different than landlines and cell phones. When cell phones first came out people would have both a land line and a cell phone. Slowly be surely that eroded to be a minority; now many people (and most youngsters) have only a cell phone.
Desktops/full-fat laptops will fade away in the same manner.
The question I leave with you is: which companies will be the ones capable of foreseeing this and taking advantage and which companies will cling to the past?