Most agree that content is key in winning the format war, and both sides believe they will be able to get out more, faster.

ENGADGET: High-def DVD sales slower than expected; HD DVD sells more units but Blu-ray makes more money

But Sony has added one key feature: the new model now supports the AAC file format, which Sony is in the process of adding to all new players.

ENGADGET: Sony NW-E005 flash Walkman with AAC support