I suppose if people keep saying it often enough, it might become a self-fulfilling prophecy.  When new users join the crypto community, "LTC=Silver" is the message they invariably get exposed to early on.  Whether or not that notion continues to be perpetuated is another matter, though.  Personally, I think Litecoin has some serious work to do to hold on to its 'silver' mantle.  If too many people start to lose interest, there won't be enough willing volunteers to say the line and spread the analogy.  Without that phrase being repeatedly drummed into people's thoughts, I honestly don't think Litecoin is there on any technical merit.  The only thing keeping it afloat is the trading volume.  If that ever dries up, it's probably over.