Basically, if a Devcoin core project was created and managed to stabilise the price relative to say dollars, that project has just become a bank. That means you have a Devcoin central bank fixing its exchange rate. Whether that's a good idea isn't even the same question as whether it's possible.
Instead of that (and this is one reason Devcoin is interesting) what if the backing is stuff? Open source development, creative commons repositories, people and their time. That creates an equity base and also a more equitable way for anybody to get involved. The reserve you refer to could in effect be the stuff that Devcoin is and will facilitate and fund. If a point can be reached where enough people and organisations rely on dvc to facilitate their work (they genuinely perceive it as earnings), and enough others support that work and progress (they genuinely perceive it as worthwhile and necessary), then you have inbuilt reserves and collateral in the simple mechanics of the currency. Any growth of a devcoin economy, dvc/fiat market, trade, stability will develop with that evolution.
That was an interesting and well thought out response.
I happen to think the Devcoin economy will be a whole lot more interesting towards the end of this year compared to what it is now.