According to recent article over at Winbeta.com, Microsoft, when asked, said the upgrade prompt will be disabled on the 29th July as well as the free upgrade to Win' 10.
If the offer get's extended then of course so could the upgrade prompt. We'll just have to wait and see.....
“Details are still being finalized, but on July 29th the Get Windows 10 app that facilitates the easy upgrade to Windows 10 will be disabled and eventually removed from PCs worldwide. Just as it took time to ramp up and roll out the Get Windows 10 app, it will take time to ramp it down.”
If the offer get's extended then of course so could the upgrade prompt. We'll just have to wait and see.....