I don't think you can say it's out of date because it is intentionally to be pegged to the dollar. Its purpose is still just that. This is just natural market reaction because market sees value in SBD as it can generate more money through upvote bots. There's no way in hell STEEM devs can prevent this from happening.
But yea, a more recent update on how the state of STEEM/SBD would be nice.
I interpreted "pegged to the US$" to mean the rate would be maintained within a range. It seems as you say, value is determined by the market and nobody is intentionally trying to keep it in a range; like for example the HK$.
Thanks for the clarification.