From my experience - this is the majority of WDW guests !!! Don't forget, the internet forum population is a very small percentage of WDW visitors.
First, I am a travel agent, and can see certain patterns among my clients. Agreed, that is a small percentage of all WDW trips booked.
First, many people book their trips many months in advance, before the discounts are announced, when the only discount available is AAA, and the AAA discounts are limited to a certain availability. As I write this, I have agents who are quoting and booking trips for clients for late August thru December 2010, some using AAA, most not. In other words, most are booking trips at full price.
Second, most of my clients would not book direct on disneyworld.com, they prefer face to face or phone contact and are nervous about putting their private information on the internet; if they did book with Disney directly, they would call on the phone. Unless these guests are aware of available discounts for their travel dates, Disney phone CM's will NOT volunteer discount information unless the guest asks for them. It is against policy to offer discounts to clients unless the client asks for them. Yes, CM's will offer upsells - but upsells mean add insurance, add dining, add Water Park Fun and More option - not offer the guest a way to save money.
Finally, even for the clients that we have booked when a new promotion is released, one of our services (like KK) is that we are on the phone with Disney at 7am attempting to convert our full-priced client's reservations to the new promotion - and only a certain percentage can be converted, as Disney only allows a certain number of rooms per resort and date to be booked with a promotion. Based on the client, we can and do sometimes move them to a different resort based on their requests - but this is telling me that the resorts where I can't convert reservations are FULL with mostly non-discounted reservations.
Disney calculates a magic occupancy number for each resort and travel date, when the number falls below a certain point they offer promotions to fill the resort; just because they lifted the black-out on Easter dates doesn't mean that the majority of guests are booked with a discount.