Copy Sony? Nope. Not sure Nintendo gains anything from copying Sony. Nintendo, for one thing, ends up having first-party titles that sell really well, and Nintendo does a far better job than Sony on this front.
Now, if you want to argue Nintendo should come up with some new IP that would be of interest to more core gamer audience, I can see that be argued. Currently, Nintendo is pretty much milking their old IP, even if it may be in new ways.
Maybe with the WiiU, they could really push some new IPs, particularly doing an RTS.