@Apple: Actually, you'd be surprised what you 'need' to get a job at a place like that. Generally speaking, it's no education at all. I mean, the very first game deisgners didn't have any degrees or anything, and a course on game design is actually a fairly novel concept, from the last decade or so.
Most of the game designers I know got into the industry in a few different ways. Some started in QA, and got promoted to designers. Some started in other disciplines, like programming or art, and just kinda shifted disciplines once they got into the industry because they enjoyed design more. Then some, probably the largest group, got their jobs by
making games. They just cobbled shit together wherever they could, making mods and crap like that.
if you're interested in working for Game Workshop, my recommendation would be to... well, I don't know much about the underlying mechanics of Warhammer, so I can't give a
precise plan, but basically, if I wanted to work for Wizards of the Coast, I'd make a set of Magic Cards, or write a campaign or new class or species for Dungeons and Dragons. Then I'd make a few more, until I got really comfortable working with the overall mechanics and feel of the respective games.
Then, get in touch with the company. All company websites will have a contact form, or careers page(Though they may be hard to find - they're generally at the VERY bottom in small print to avoid getting any fan with bright eyes applying). Send them an email with example of your work and resume, and ask them to keep your resume on hand or bear you in mind for future opportunities. IF they have a job open you're interested in, apply for it. Keep on applying, try and get yourself a name with them, and most importantly, keep building units or game types or campaigns or whatever you're making for them, to keep getting better. Put them into practice so you can balance them, get other players to test them at games shops on the weekends or something.
Go to conventions and try and meet some of the people in the company. Be polite with them, and not to pushy, but agressive at the same time. Let them know you're interested, ask them for any advice or if they know about anything happening. Be pleasant, and try and get to know them a bit.
The Hierarchy in the games industry is founded on two things: Who you know, and what you show. My degree has gotten me
squat so far. Based on degree alone, I
should have gotten a job at WB, but I was rejected for limited technical experience, because my portfolio wasn't up to snuff. I understand and accept that. What you have to show will go a
lot further than a bit of paper. That just makes the suits happy.