You need to get the latest drivers from Intel, as they aren't part of the kernel that ships with FC4. You can get them through
http://www.intel.com/go/linux, Select Build from the tabs, then click on drivers under related links. You can download one of the rpm files for one of the Redhat distributions, as they have the source rpms.
Fedora Core 5 should have this support when they release. It's a little shakey right now, though.