I say spend the money on the parks!
The one thing that no one else has mentioned is that literally thousands of people a week, go to the parks that don't stay at the resorts. That's a lot of revenue from people who won't come back (and possibly stay at a resort next time) if the parks aren't well maintained or aren't worth the ticket price charged for a park that can be seen in half a day.
Also, there has been discussion about Disney's ability to get fill the resorts. Sure, the Value Resorts are busy, and the other resorts aren't. The solution here, isn't building more value resorts, it's reducing the rates at the moderates. The cost of renting for a luxury hotel room is usually between $10 and $20 (I was a cost analyst in a hotel, and have worked in the hospitality industry for the past 18 years, and granted that cost reflects the luxury hotel market in Dallas, I can't imagine that it's much different in Orlando, the hotel rack rates for luxury hotels here being fairly similar to the Moderate and Deluxe Resorts at Disney) and it's more cost effective to have some revenue coming in for each room than it is to fill only half at a high rate. At any rate, even with the "deep discounting" we're seeing at the resorts, there is still a great deal of mark up happening, which if correctly managed could spread the crowds across the the World instead of concentrating them at the All-Stars. Not to mention that for a lot of people, once they've experienced a nicer level of hospitality, they're hooked and will spend the extra money next time around . . .
Just a couple of points to ponder . . .