Serious question: why do we keep repeating this experiment? Not that I mind, I just am curious why do we keep building bigger and bigger vacuum chambers just to drop a feather and a hammer over and over.
Similar large facilities exist at many national labs, and they are used only sporadically. For instance, in the Bay Area, NASA Ames has a very large (11 foot square) wind tunnel that can reach Mach 1.45 (http://www.nasa.gov/centers/ames/orgs/aeronautics/windtunnel...).
The inflatable bags that landed Spirit and Opportunity on Mars were tested in Mars air pressure at the Glenn vacuum facility: http://www.nasa.gov/centers/glenn/about/history/marspbag_prt... . Many spacecraft undergo "thermal vac" testing meant to simulate space conditions.
But to answer a more general question. We shouldn't stop repeating experiments just because they were done before. The scientific method works as long as we keep reproducing results. Sure, this is a trivial result, but it's something every kid should have done by its own in the school physics lab.