Each room in the con space is wheel chair accessible. The panels, events, workshop, viewing rooms, and even the exhibitor hall. All the rooms have double doors for entry so there will be room to get in and the hallways and corners are all more than wide enough (so long as your fellow attendees are cooperative). The only room that might be a problem is the Gaming room because of all the consoles and DDR pads and cables. I will mention it to the gaming staff, just in case.
As for parking and the actual rooms in the hotel, the main lot and the guest rooms are accessible. I'm not sure how much room there is to maneuver once inside a guest room, that's something for the hotel (but I doubt they'll have an answer for you). The hotel will be using the parking garage across the street, this has a long entry ramp (with no special sidewalk for pedestrians or wheelchairs) but it does have an elevator. The other parking options may not be as accessible since they are scattered around downtown Vancouver.
The only complication I forsee for an attendee in a wheelchair is pre registration. the line will be running up to the door in front of the ramp, so a yojimbo would need to be called to "part the crowd" and let you up. One should be stationed outside those doors though so if it does come up they'll be able to make way quickly.
Edit: I realized quickly that I should mention that the Exhibitor's hall will be accessed by a driveway ramp that is steeper than normal (The elevators will all be locked at that level for the duration of the convention. That is, steeper than the usual wheelchair ramps at entrances. This may not be an issue but I did not want to give the wrong impression, a hand powered wheel chair would be rather difficult on such a slope if it was not expected. I don't want to be too presumptious.
Since you signed up on the volunteer list, I'd suggest you come by on Friday and become our "ADA Litmus Tester" to make sure that nobody sets up the panel rooms with stuff too close to the doors. You could show they yojimbo what to keep an eye out for to help other wheel chair using attendees get around easier.
