Patti,
Many people would tell you to go to Spoodles at the Boardwalk, but by the time you come to run the marathon, it will be gone. Didn't want you to come here and miss out.
Replacing Spoodles will be a new restaurant called Kuzzina. It will have a mediterranean-inspired menu created by Cat Cora (of Iron Chef America fame). She does a lot of Greek, but when her restaurant opens in the fall of 2009, it is assumed that you will find a lot of pastas too.
Another semi-new choice would include
Portobello at Downtown Disney. Recently updated, it has moved from a mostly southern Italian menu to better represent other regional tastes. So not quite as many pasta options, but more than enough for your needs. Prices are a bit more reasonable now too!
A third option would be
Il Mulino at the Swan Resort. The most expensive of these, it has a wonderfully contemporary yet warm setting.
I would trust any of the three, but look up Kuzzina a little closer to run time to see what the menu might hold.
Have a magical vacation (and a great run!)