Will Nintendo have their handheld throne contested again? Or is Vita the last..

[Metrium]

I doubt anyone will directly challenge Nintendo the way Sony did. I doubt we will get a ''psp3'', Vita will porbably be Sony's last attempt at the dedicated handheld market.

As for Nintendo, it is really hard to see in the future when it comes to handheld and even consoles in general. They may go for a 3DS successor and keep on competing with smartphones or maybe they will take WiiU's concept further for it's successor and have a full home/handheld hybrid removing the need for a new handheld.
Atleast one's thing for sure, no one will never try dipping their toes in the dedicated handheld gaming in the future except Nintendo IF they continue to do so.
Or Wii'U's will be Nintendo's undoing, they go bankrupt and never hear of them again (sarcasm).