It's enough to make you cry. If physical disc formats really do have some shelf life, then Royal Digital Media's new optical disc format may have some worth, but if it's at the expense of Blu-ray, it's going to play havoc with the consumer. Technical part first: Royal Digital Media has developed a 100GB-capacity disc which can handle four hours' worth of 1920p HD video -- "the next generation of high definition" according to the company. The killer part of the equation is that the cost of the discs and players is expected to equal those of traditional DVDs, therefore undercutting Blu-ray...