I am thinking this many days.
There are many wireless thermometer on the market. The cheapest is $26 and it works.
How many would like to spend $80 for an igrill, which is indeed another wireless thermometer, only difference is using your iPhone instead of remote handy set.
If I develop a thermometer with WIFI, you can monitor temperature from you iPhone, and even via Internet when you are at your office. How many would like to spend $60 for this WIFI thermometer