I have a live marketplace version of my application, and now want to start developing my next version, but want to be able to have the newer dev 'upgrade' (for testing) and existing live version (for demoing) both on the same device, but I dont want to create a whole separate project to do this.
Any ideas?
It's not possible.
The closest you can do is change your package attribute in your manifest during your initial rounds of development, and change all your code to adjust to the new R.java location that results from the new package. Then, you could have both old and new installed, though the "new" won't be an "upgrade" of the old, but rather a fresh install. And, of course, you presumably will want to change the package back and do testing of actual upgrades somewhere in your dev cycle.