The first thing that comes into play to an artist using a computer is economics. We say if I could have one machine that could do it all (I only can afford one), what would that machine be? That totally depends on what kinds of artistic work/play we are planning to do. So, let's see, digital art requires at least.......... I can't answer for all you pixel pushers so I won't. For me it goes like this:
Some kind of laptop I can carry around to dabble and doodle with, not necessarily my main work horse computer. If I lose, misplace or it gets stolen, my doodle machine can be somewhat expendable. I don't want to carry around a $2000.00 machine without Lloyd's of London backing and a full replacement warranty. This doodle machine can be new/used/inexpensive but must run my idea developing software. Of course I'm a Linux and open source software guy.
Then I will need a work horse computer that stays locked up in my studio. I could then use the jump drive or e-net to move files to this studio machine to have the full weight of graphic power push ideas in any direction.
If you only have one machine to do it all and you want a laptop, you will want a big wide screen, fast processor, maximum memory, extended battery life, etc, etc, etc. You want a desktop in a laptop wrapper. Good luck and second mortgage with that.
I still have a vision in my head of the artist roaming the country or city with his box of paint, pallet, easel and small canvases, all situated so he can move about, setup, paint, catch some rays, pack up and go. When he is done capturing he goes to his studio with his visions nailed down and incorporates them into larger canvases. Well this is more or less how I work, only I have sketchbooks and ball-point pens. I'd like to replace this with a laptop.
I have to say though the reason I can get away with doing much on the cheap is because I value the simplicity of 2D design. Many computer artist are into processing power to do 3D graphics, animation or run engineering software, complex programming and imaging software. You must have the equipment to be able to comfortably run the applications you need. The more power you need, the more display options, the more the costs go up. This is why I want a dabble and doodle machine and then also a studio machine.
Another thing I have been impressed with is backup. Especially with artwork, get USB jump drives or USB hard drives to save your work on. Nothing is worst than an OS crash or drive failure and your work is on the same drive as the crashed OS. Recovery services can be expensive. Also this USB drive allows you to carry your work with you, plug in to other computers. With some Linux you can even install the OS and apps on the jump drive and use them if the computer can boot from the USB device. I'm seeing a new cyber superhero wearing a bandoleer of jump drives like a utility belt, ready for anything. So, a laptop with a smallish hard drive is of little concern, rather USB ports is the key along with jump drives.
Sometimes the latest technology is a desire stirrer upper that has nothing to do with getting the work done, just spending your money. Step back from the edge, away from the "having the latest" excitement. I know many handymen and artist who can't give up an old brush that works fine. You pros must be competitive in your market, us dabblers and doodlers have a more relaxed pool of resources, challenges and expectations.
The last stroke of genius for artist is output devices. I've seen a video projector that fits in the pocket and used LCD's can be had very cheaply. Multiple display electronics are out there and we can't even adequately touch printer technology. If the typical desktop printer can put out digital photos, you can bet it will do justice to your digital art work. Now, multiply that times 10, wide format inkjet printers can do poster size and larger and can get pricey if you want to print on more than paper. I can get very exciting if you let it.
I am just poking at a niche, a lot of digital graphics never leaves the screen. Most folks when they think of computer graphics probably think web stuff, or game graphics, movie special effects or cartoons. The digital art world is plenty big. Got a big screen TV, what do you do with it when not watching videos. Computer input makes it a huge multimedia display.
Yeah, I know you can exploit all this with MS or Mac but this is Linuxville.