I've only had my Nexus 7 for a month, but I'm finding myself using it constantly whenever I don't want to be stuck at my desktop. It can't be beat for reading, and I find it very useful for writing. I am a very bad hunt and peck typist, and I find that I can actually write at least as fast (and probably faster) using Swype on my tablet or phone as I can on my desktop. Google Docs and Evernote both work surprisingly well on it and in some ways better than on the desktop client thanks to the baked in share features in Android and the ability to add camera scans. As long as I don't need 3G connectivity or extreme portability, anything I can do on my phone is far easier and more enjoyable on the bigger (but still not cumbersome) screen.
Corollary: Use it as a second person if you're mixing on a digital audio mixer either in a live or recording studio settings. Difficulty: Very narrow focus type use.
Many digital mixers these days have networking capabilities via Ethernet port (I can count on one hand the digital mixing desks that has Wifi built in. Almost none). Add a router and you got, with an iPad (and solely with iPads sadly), you have a remote control to your desk.
With the right apps and a bit of tweaking, you can even access your DAW straight from iPad, and control nearly all aspects of your DAW from there without needing to flip back and forth and what not.
Again a very narrow slice, perhaps, but it does make for a great tool for automation and a second pair of hands without necessarily needing an actual second pair of hands.
Ha HA! I no longer have to choose between convenience and power, as I'm typing this on a Sony Flip. Real keyboard, real browser - flash may suck, but its everywhere and there are lots of things you cant so with mobile browsers. Real storage and real access to the network drives (suck it, iPad). It even has a real, pressure sensitive digitizer (suck harder, iPad).
Now, I can't lie - this is way more than a 1lb take-everywhere device - but it's so much nicer to have one device rather than two when I'm on the road, and it weighs about the same as my old iPad and netbook-sized laptop I used to take. And, hey, I still have the old iPad for checking FB and watching Plex.
I recently installed Splashtop. However, I'm not using it for remote access but for mirroring my laptop to it (maybe there's a better app but this is what I tried first). I've been using Lightroom and Photoshop on a cheap Toshiba laptop now that my 2007 Macbook Pro is too slow for them. The laptop screen is awful so I'm able to better see what I'm doing on the tablet screen (but physically working on the laptop still). This is no substitute for plugging into a calibrated monitor but I don't have one, so this does the job.
The main use for my tablet though is for Netflix to put on kids shows for my daughter. It works well for times that I'm at work and my wife needs a shower or something, it can keep my daughter entertained.