the rumor says in the lifespan of the D300s "so wait" That could be long wait.
Not too long. The D300's lifespan was only about a year, so I would expect the D300s to last about a year, too. Besides, Red and Canon (and maybe Sony and Panasonic) are all trying to reach this goal. If they're late, they can lose a lot of market share.
One of their biggest obstacles, IMHO, will be to get NLE support. Red created their own Raw format (RedCode Raw), and was able to get support from the major NLE's, but they were/are the only one in that category, and it took a lot of time. Red had to create some of their own utilities so that people can use their output. Nikon will have to create their own utilities, too, and in a crowded marketplace, it may be a while before they get NLE support.
Maybe Adobe will create something like Adobe Camera Raw, but for video.