According to a WHOIS domain lookup concerning the site persona5.jp (which is currently acting peculiar), Index Corporation have registered aforementioned domain name as recently as June 25, 2013.
This could potentially be a sign of upcoming news regarding the title, or it could also be some kind of mistake. It could also be that they are registering the domain as a precaution for the future. Who knows, but in any case, it’s a new sign of potential life regarding Persona 5 and it is exciting.
Here is a picture of what is currently displayed on the website (which is to say, not much):
And here is all of the information regarding the Whois domain lookup (note the registrant as being Index corporation):
[Domain Name] PERSONA5.JP
[Registrant] Index corporation.
[Name Server] dns1.onamae.com
[Name Server] dns2.onamae.com
[Created on] 2013/06/25
[Expires on] 2014/06/30
[Last Updated] 2013/06/25 16:39:27 (JST)
[Name] Whois Privacy Protection Service by onamae.com
[Postal code] 150-8512
[Postal Address] Shibuya-ku
Cerulean Tower 11F