Western Digital added 750GB and 1TB SATA drives with up to 32MB cache and enhanced vibration and shock tolerance.
Translation: Huge drive. Fits your music, movies, pics, games, docs, and about 1,600 full-length MPEG/Divx movies or hundreds of uncompressed DVD movies. Huge cache. Lets you access them fast. Shock protection. You could walk around shaking it like a maraca, and it would still work.
WD RE3 1 TB (model WD 1002FBYS) and the 750 GB (model WD57502ABYS) hard drives are available now for $249 and $199, which may be the best part.