Why is this important? If this new coin is sooo superior, exchange your Bitcoin holdings into this new coin and forget Bitcoin.
It's important because once such superior currency is introduced and becomes known, the selling pressure on Bitcoin will make it such that the Bitcoin holdings will become worthless faster than it can be exchanged for the new currency - unless one foresees the outcome way before others do (which is why I'd like to be involved in these sorts of discussions now).
All upcoming bitcoin vulnerabilities or other unforeseen issues will be fixed as the bitcoin devs want to maintain their wealth.
If Bitcoin technology is such that it can be fixed over time (which goes back to my original question), then that's great - exactly what I wanted to hear.