Filed under: HDTV, StorageNow here's a rate of progress we could get used to. Nary a month after Pioneer trumpeted a 400GB Blu-ray Disc, out pops another press release from the firm boasting about a 500 gigger with a score of layers. Based on research at its Tokyo headquarters, specifications have been drafted for an incredibly capacious 500GB BD. Granted, this very company already had plans for a 500GB optical disc nearly four years ago, but there's no time like the