A rare dissenting opinion, you bring up points worth discussing. If there is a marketplace to sell steem dollars directly, you may be right. It could be a repeat of BTER creating a direct BitUSD market, removing the need to buy BTS at all.
What is your opinion on what will happen with the SteemDollar? Is there anywhere to sell them, or are they only able to buy Steem?
There is nowhere to sell Steem Dollars yet because Steem Dollars don't yet exist. The developers have said they hope to have direct SD/BTC markets either immediately on July 4 or soon thereafter. The original post makes a good point that this is not worth much unless there is demand to buy the Steem Dollars.
I was wondering if there were concrete plans for it, but have not seen anything official.
If there is to be an official place to buy\sell Steem Dollars, it might be good idea to tell people where that is beforehand. Some advertising about the upcoming "sale", might bring in enough buyers to lessen the impact.