>What becomes of existing software patents, for example? Purists may say these are not "property" but massive dollars have been paid for the rights to own them

>What becomes of existing software patents, for example? Purists may say these are not "property" but massive dollars have been paid for the rights to own them and there will be huge resistance, not to mention constitutional objections, over any idea that these suddenly should be rendered worthless by legislative action. It is the same problem you have with an transistion. This was studied a lot in economics, specially around the socialist transistion. One view is this, pay out the benefiters of the old system just so you can get the institutional change. Pull the benefiters to your side. This could be hard with software patent but it is one way to get to institutional change.