The precious whitepaper clearly mentions that a peg is intended, but it is imperfect. I've cited that two-way conversion segment before as well, but now I'm beginning to wonder whether @smooth is correct in that a severely gimped reverse conversion mechanism would actually set us in the right direction and achieve the peg more quickly.
From my observations, people that are against the peg like that SBD is worth more than a dollar. We don't have to peg the SBD to a dollar. We can peg the SBD to 2 dollars (for example) :P
Having a peg is obviously better than not having a peg, and I can see where the proponents of the peg are coming from in term of having a stable base on which to offer services without having to resort to on-the-fly conversions or even having to worry about price fluctuations at all.