Quote from Pathologic
PC version didn't have offline to avoid potential security issues which don't exist in a console version. PC will not get offline mode - don't get your hopes up.
PS3 is hacked, it is possible to cheat in games already (chipped consoles will get banned from PSN eventually, but Sony is slow enough to let cheaters have their fun). And as other stated, PS4 will be based on x86, which opens up the possibility of running PS4 stuff on PC, especially on new AMD hardware (with HSA and GCN).
Potential security issues very much exist on consoles.