Do the development as crowdfunded stages with each product produced running autonomously. Enable coins to be burnt from one development stage to the next. Each stage runs as a decentralized, autonomous protocol. Whole new paradigm for altcoins. Perhaps I will be the first to test the model (pending decision involving this thread). Maybe Gmaxwell is reading and can apply this to the general concept of side-chains.
Adam Back already proposed burning coins as an upgrade mechanism, which he called a one-way peg. It was that idea, in fact, which directly led to side chains (i.e. bidirectional burning or two-way peg).
I personally believe that spin-offs are a better model for upgrades than burning but the argument could be made either way (and there may be technical reasons to prefer burning).