The point probably being that these features are specified in the standard, but aren't implemented everywhere yet. This isn't lock in, because other browsers will presumably implement them soon(tm).
This seems to be a point a lot of people are making, but it isn't really true. Most of the features shown in these demos are not part of any web standard. HTML5 is actually not a standard, but even if it were this would still be only partially accurate.
In reality, all of the CSS transforms and effects (and plenty of other Safari features) were created by Apple without input from any of the other browser vendors or standards bodies. Some of those things have been picked up, some haven't. I actually think this is the right way to do things, and I don't want to give off the impression that I don't appreciate what the Safari team has spent the last few years doing, but I'm also not wild about letting Apple distort the picture for the sake of scoring PR points against flash (which is what this website is all about).
