PS2 could mean so many things.
Pretty Sweet 2
Personal System 2 (IBM) (PS/2)
Public System 2
Pilot Service 2
so youre pretty safe - it's generic enough.
Playstation though is a registered trademark, and they (Sony) will FIGHT YOU TO YOUR DEATH if you abused it!
Besides, PS2 and Playstation are all taken in major TLDs - yes, by Sony!