This apparent response to concerns over the battery life of the system - which is quoted as around 10 hours for music and two hours for movie playback - places the problem firmly in the developers' court. Sony apparently intends to include a "battery emulator" as part of the PSP development tool set, which will evaluate the projected battery use of a game over an extended period of play. Titles are likely to be judged based on how many hours of play a single battery charge can provide.
However, as yet it's not been decided what an acceptable level of power consumption actually is, with the draft documentation apparently leaving out hard figures for Sony's battery life projections in games. Apparently some developers have speculated that Sony may be waiting to see what kind of figures are achieved by headline titles such as Metal Gear Acid and Gran Turismo 4 before "drawing a line in the sand" on battery life.
While the PSP has been generally praised for being exceptionally easy to develop for, this new restriction will add a layer of complexity to the development process - and will almost certainly rule out the type of disc streaming technology which has become commonplace in PlayStation 2 titles such as Grand Theft Auto 3, as constantly accessing the disc in this manner would seriously impair battery life.