>What do you think is the best way for small businesses and sole-traders to plan for this, since we know that larger players are moving down from the over-served large business IT arena into the small/middle-sized segment that has been enjoyed by smaller players for over a decade?

We work with a number of smaller firms and if, they have a product which meets our needs, and they are a small shop, then either we have a source code purchase option or source code escrow. If not, we won't do business with them.