The first WDW marathon we went to was January '01. For the package, NO discounts were offered. And the only plus was being able to attend a pasta dinner.
I figured that pasta dinner was going to cost us around $400. Needless to say we didn't book the marathon package.
For this year's marathon, I didn't even bother checking for packages.
We bought AP's and got a great rate at ASMo for $55 a night with tax, and really enjoyed the resort.
We are planning a repeat visit for January '03.
Although the expo will be at CSR next time. So I suspect more marathoners will stay there this time.
BTW -- last January DH & I attended the Disney Deads (Runners) off-site pre-race pasta dinner.
And the runners are pretty low key. The most inconvenience I experienced was running out of hot water at CSR January '01. (Not a mjor inconveience, but it did happen to me and other guests at CSR that morning.)
The runners have to get to Epcot VERY early. Most get up around 2 - 3 a.m., they shower, and special buses take them to the start line at Epcot.