NEAR will hopefully also tell us about the origin of meteorites.
About 85% of meteorites are ordinary chondrites, which are made of iron and silicates such as olivene and pyroxene. Since S-type asteroids are the most common asteroids, they're thought to be the parent bodies for ordinary chondrites because of the numerical corelation.
Right now, we don't have enough information to compare the compositions of the two. The data from NEAR ought to conclusively tell us whether or not Eros is an ordinary chondrites, and it will allow us to calibrate the data we have on other asteroids to determine if they're parent bodies for ordinary chondrites.