It’s looking more and more likely that Ratchet & Clank Nexus/Into the Nexus will be seeing a PS Vita release now that the game has been rated by PEGI for PS Vita. The PEGI listing appeared on the PEGI (Pan European Game Information) website and twitter account earlier today.  No official announcement or confirmation a Vita version of the game has been given by either Sony or Insomniac thus far.

— Original Listing from PEGI —

Ratchet & Clank: Nexus 
Sony Computer Entertainment Europe
The content of this game is suitable for persons aged 7 years and over only.
It contains: Non realistic looking violence towards fantasy characters – Violence that is set in a cartoon, slapstick or child like setting that could be upsetting to very young children – Pictures or sounds likely to be scary to young children
System: PlayStation Vita
Genre: Other
Releasedate: 2013-12-04

Owners of Ratchet & Clank Nexus on PS3 may have also seen the trophy listing on PSN which, interestingly enough, shows it as a PS3 and PS Vita game.

2013-12-04-200346

Via PEGI / PEGI Twitter