There's been a lot of talk recently about preventing the various DACs from competing with each other, by merging them all into Bitshares. The DACs would be competing if each one of them (being blockchains in their own right), had to implement its own, completely separate BitUSD. This would indeed be disastrous and confusing, since you'd have a set of differently priced(!) and differently liquid BitUSD markets for each asset.
What I don't really understand is why there isn't a feature in the core to allow cross-chain atomic operations, then you could still have each DAC be its own blockchain (since they need to store their state somehow), have the asset which represents the DAC listed as a plain user created asset on the main bitsharesX DAC, but also allow operations on the local DAC's blockchain to be synchronized atomically with the bitsharesX DAC blockchain when needed - for example, paying dividends to asset holders, or a unlocking a purchase of music via BitUSD.
That way you can keep the separation of concerns of having a blockchain per DAC and also pave the way for non dacsunlimited 3rd party DACs to have the same advantage of sharing a nice, singular, liquid BitUSD market.
Anyone care to enlighten me?