Well, the original intent for Offline Mode was always for it to be an indefinite option. The issue was, the system with which they used to store client credentials locally (centered around the infamous .blob file) was incredibly buggy. This often lead to many having trouble with Offline Mode. And then, almost two years ago, a new bug had cropped up that was causing some systems to lose the client credentials after only two weeks, requiring the client to be logged into the Steam servers to reacquire the credentials.LetalisK said:I think this has been the case for awhile. The only difference is Valve has made it an official feature rather than just something that happens when you unplug your internet for a minute while launching Steam. Before it was made official, Steam did have that annoying bullshit where if you didn't go into Offline mode while online, then it wouldn't let you start in offline mode later when you were actually offline. However, the work around, as I quickly found out, was to physically remove your internet connection before launching the program(you could resume internet connectivity after with no issues). Steam would detect that you had no internet and would simply launch the library in offline mode. I don't know if this worked if you used wireless internet since I always use a hardline, but the work around of removing the CAT5 cord was simple if retarded. As for the pinging back to home every once in awhile, I used this for a several months straight in 2012 when I had internet, but it was so shitty that I couldn't connect to Steam online with it.
As of late last year, Valve phased out the old system and have replaced it with a system that works with incredibe consistency. Provided one has Steam set to remember a user's password (i.e. client credentials) locally, they can go into Offline Mode at any point. Whether they're already online, just lost connection, or booting Steam for the first time, it (should) go directly into Offline Mode.