With OTA updates adding only changes and not complete firmware....

[Baggy Spandex]

Might this make it possible for the future exploits to remain intact when upgrading, as long as the exploit isn't patched?

This would be absolutely wonderful, and I guess only time will tell. Something to think about though.

 

[musicmax]

More than likely it means that Apple will hash-check your existing iOS and if yours doesn't match due to JB you don't get the update.

 

[eastercat]

Let's be realistic. Apple has to show it's doing everything it reasonably can to stop JB/unlocking.