Heh, at least Sony has such a huge share of the digicam and videocam market that it doesn't really need to worry whether anyone else is using their Memory Stick standard. In fact, in their case, they seem to be deliberately keeping the Memory Stick proprietary-only instead of attempting to make it a standard, so that owners will tend to be locked into their segment of the market.
Olympus and Fujifilm aren't in such an enviable position at this moment, though. Really silly of them to introduce this xD card instead of CF when they're behind in market share. On the other hand, there is a rumour that there will be some kind of adaptor that will make the xD card compatible with CF slots. If this is really true, then maybe they will stand a fighting chance (until the "next better player" comes along... sigh).