Sure, it may not help in THAT case but it would help with people hoarding patents for the sole purpose of suing others. There isn't going to be a single solution that solves the patent problem. It will be a combination of rules like
1) you must have a product on the market using the patent
2) no business method patents
3) software patents are limited to 2-3 years
etc etc
The problem with "must have product in the market" is the same as with the idea of fixing the domain name system by adding a requirement of "use it or lose it".
Who gets to decide what "having a product in the market" means?
It's impossible to generalize this to an objective set of rules. Thus we'd soon be back on square 1 (read: in the court room).
