Depending on routing, the course could run to 800+ miles (1300+ km). You will have about a week to cover this distance, which will mean average daily rides of well over 100 miles (160 km), though I don't doubt that many will be faster than this.
Many of the approach roads to checkpoints are unpaved. At least one checkpoint is accessed by what i beleive to be a bikeable trail. Take this into account when choosing your equipment. I won't be using roads that aren't passable (in my opinion) on a touring bike - you won't need a full-blown mountain bike for this - but I'm not sure your super-fancy lightweight road machine would be the best choice...
Be prepared to ride nights, go without sleep, and deal with a variety of weather and road conditions. The wind on the Pacific Coast does tend to blow north to south, so be prepared for headwinds.
Watch out for logging trucks and narrow road shoulders, especially at night.
This is not normal bike touring - though it will be completely possible to finish within 6 days at a fast touring pace, carrying a tent, a stove, and multiple changes of clothing. Although minimalist equipment is recommended, what exactly that means is up to each individual. However, under no conditions should you sacrifice items that may save your ass in the middle of nowhere (i.e. tools, spare parts, emergency food, water-carrying capability) in the interest of lightening your load. Pack every tool and spare you can think of that you might possibly need on the road - think what will cost more, the extra weight of the tool you'll need if you don't have it with you, or a bus ride home when you don't have that tool. Don't second-guess Murphy's Law.
Choose your clothing carefully - weather will run the gamut from hot to cold, sunny to rainy (they don't call this area coastal rain forest for nothing...), night time temperatures may be cold, and there's always a good chance of windy conditions. A good lightweight rain jacket might be one of your most valuable clothing items, as will some light base layers.
Carry plenty of water, and refill as often as possible. If you're not sure where your next good water stop is, have a full reserve bottle until you know where the next water is. Over this course, it's unlikely that you'll into a stretch if road without any chance of finding drinking water.
Eat. Small amounts regularly is the way to go. Some people who do endurance events of this length depend almost exclusively on the energy goo products currenty available, but while that will work, I don't think that's any way to live. Eat quality food, in small portions. Save your candy and chocolate until you're bonking on the way into a place where you can get better food. If you're putting on the mileage in the late night/early morning hours, carry food for the duration, as you don't know the hours of the stores down the road.
I realize that there's no real way to catch someone who might be "cheating" on the course - using vehicular support, taking train or bus, fudging your checkpoint info, or whatever. I'm relying on the entrants' honesty and simple sense of pride to keep the race clean. The cyclometers are there to confirm mileage traveled, but this obviously isn't absolute in a race with no fixed route or manned checkpoints. Personally, though i know it may not mean much to anyone else, I'll be immensely disappointed if there's cheating going on. "Disqualification" for cheating will largely consist of being shunned by your fellow riders, outed on this webpage, denied recognition, prizes, and your commemorative t-shirt.
Remember: you may be "racing", but it's not worth killing yourself over. Don't take risks you shouldn't, know your limitations and those of your bike, don't ride exhausted, drink plenty of water, eat plenty of food, listen to your mom, etc. This is an unsanctioned, uninsured, and possibly illegal race, and there is nothing for the organizers to fall back on in the event of emergency. Take responsibility for your own actions and decisions. The last thing anyone wants to do is receive a medical or legal bill over any of this. I'm taking a risk in organizing this - please help me keep that the only risk involved.
Oh yeah, and don't forget to take the time to look around, appreciate the area you're riding through. It's a beautiful area to ride through - for the sake of your memories, don't just blast through with your head down... stop, take pictures, explore things...