When he said "Death, where is your sting?" he referred to those raptured, not to the rest who are left behind.  I understand what you mean, that it is not complete victory over Death if everyone is not saved.

My personal itty-bitty understanding of this is that eventually Death will be destroyed for everyone.  But that will take a while.  Around a thousand years, the time of the Millennium.  Then, Death will be destroyed for everyone who will accept the goodness of God.  Others?  Will they go down to Hell and suffer forever?  No, I don't think so.  I agree with Sal Smario that some will just sleep forever because they could not wake up even with the blasts of God's trumpet.  But no one gets stung forever.  

However, I do not offer this as dogma.  I believe we do not understand the whole picture.

I just know that Paul was referring specifically to those resurrected and taken to the kingdom in the rapture event when he said "Death, where is your sting?"

Mariel Rowina