Betanews is reporting that The RIAA has managed to shut down WinMX, a popular peer-to-peer file sharing service.  In addition, eDonkey has apparently been shut down by Reuters (though its website remains up).

Since most P2P networks today are decentralized, eliminating a P2P network completely is nearly impossible.  However, the RIAA strategy seems to revolve around shutting down "super nodes" that, as a practical matter, cripples a given P2P service.