I have been working on a solution in my mind for a couple weeks now....I will explain it once Asset Exchange testing starts and we play around for some time....right now it's only in our minds....at least I had the luxury of speaking to a PhD who has been testing the Asset Exchange for some time now but there are still black spots in my thinking.
Best of luck with it - but my guess is you end up with something like "Bitshares" who think that just because you call something bitUSD then it will magically be "worth" 1 USD because of it being a "prediction market".
I don't think that holds water at all nor any kind of other "pegging" unless you are talking about the kind of "pegging" that governments do (like Hong Kong's pegging of the HKD to the USD) which is not at all what I think people interested in "decentralised" solutions are looking for.
Any type of "pegging" is centralization. This is the antithesis of Nxt's ideology.