[dalore]

Not necessarily. It would be bound to be have found at some point in time. The article mentions it took at least a year before anyone knew about it.

And perhaps there is an even more technical worm out there still hidden and stuxnet was merely a first draft.

[bluGill]

perhaps, but perhaps the creators don't know of any more holes. Or perhaps the creators knew about more, but the focus on security that this created resulted in not just the holes stuxnet used being closed, but the others. Or perhaps the creators know about more, but their targets have added layers of security and so they can't actually get their next worm where they want it.

A lot of unknown. Those who's job it is to secure systems have their own tricks.