Its hard to take either particularly seriously.
On the one hand you have the Wiimote clone from Sony which also happens to look quite expensive but so far lacks a single truely compelling experience that Sony could mention at its big unveiling.
On the other hand Natal hasn't really been shown off in any practical sense, however it is interesting in that its a different experience to the original and the clone.
I see both their strategies as such:
Sony are hedging their bets on already developed mindshare and developer expertise. Whilst Microsoft are hedging their bets on creating an interface which would be useful in the absence of any interesting games in that it can be used for a media centre as well. Neither interface is particularly good at this moment in time as a catch all interface for all the different groups whom may want to buy a console or whom may become interested in buying a console.
Microsoft won't have a truely good interface until around 2015 which is where the 5 year comment comes from. They need to leverage 3D adoption and improvements in camera sensors before Natal 2 will be of any real use for anyone. Natal is in essence a holding action, just as Xbox Live on the Xbox 1 was an original concept to build towards an effective implementation of the Live network infrastructure. Natal will probably have reasonable adoption for this generation but its only a first step and the real event will be the next Xbox to truely see the capabilities of the interface.
The Sony wand on the other hand is an attempt to win back marketshare and extend the useful life of the PS3 for this current generation. They'll throw reasonable support behind it but we'll see how serious they are when and if we see them allocate their tier 1 studios to the project. Because its so similar to the Wiimote I can't see them making much headway especially as part of the reason why anyone would have bought the PS3 is that they considered the Wii and then decided against it for various reasons. So essentially Sony need to get their core fans interested in the interface before the next generation because these are already likely people who showed disinterest in the Wii in the first place.
