Hi Sirius,
I've done the West Coast Trail three times (1996, 1997 & last year). It is an absolutely unforgettable and unique experience, which is why I've done it three times. I would be happy to share thoughts with you here or off-line.
Here is my set from 2007:
http://www.flickr.com/photos/sockeyed/sets/72157601157129504/
Are you going south to north, or north to south? If you start at the south, you'll have by far the hardest section at the beginning, and you'll be carrying the heaviest pack, but you get to look forward to easier hiking as the trail goes on. South to north is my preferred choice.
Weather makes a huge difference. Every time I've done it, it has been wet and VERY muddy. You spend more time going side-to-side trying to make forward progress through the mud. Folks who have done it in the dry wonder what the big deal is.
Goretex doesn't work on the WCT, trust me. After my first very wet trip (in March 97), I learned this. It just wets through. Instead, wear synthetic and fleece underlayers, and a wind-proof shell, and just get wet and keep moving. When you get to camp, change into something dry and put on lightweight waterproof clothes there (goretex is OK, but coated nylon is fine).
Definitely wear gaiters to keep out the mud, water and sand, and definitely full-on leather hiking boots.
Definitely bring trekking poles - they will help stabilize you, and they will help you poke around in water holes for solid ground. Also bring a waterproof pack cover. Mountain Equipment Co-op in Vancouver is a great place to get any gear you'll need for the trip.
Try and hike on the beach as much as possible. This of course will depend on tides, so keep a close eye on your tide table (you'll need low tides to get around certain headlands).
Take the water taxi back to your starting point (assuming you've left your car there). It's wonderful to see the trail from the water, and the fellow who drives the boat (Brian) is an amateur biologist who tracks orca pods in the area. Chances are you will see the whales.
In terms of cameras, on the last trip I carried my Bessa R4M with the 28mm f/3.5 on it (and the 40/1.4 which I used once or twice). The 28mm is very well-suited for the kind of shooting one does on the trail, but a 15mm would have been nice from time to time too. For more foul weather, I had my Olympus Stylus Epic with the fixed 35mm f/2.8. The Bessa was kept in a Newswear pouch on the hip belt of my pack and the Epic in a small Lowepro pouch, and I had a small roll-top drybags for the Bessa. When it got foul out, the Bessa went in my pack. In terms of film, I shot Fuji Reala in the Bessa and Superia 400 in the Epic. While I shoot a lot of b&w, I would definitely recommend shooting colour on the Trail.
Here's my R4M on day 4 at Cribs Creek:
A few other images...
The "Wet" Coast Trail:
Bonilla Point:
Ladders:
Cable car across Carmannah Creek:
Fatigue:
Crab at the half-way point! Worth every penny (along with the burgers at Chez Monique:
Near Nitinat Narrows: