I believe the reason Verizon won't activate the Sprint TP is simple.
Support. Sure most on this forum are technologically savvy enough to get the phone working and with the support of this forum can overcome most issues. What happens when we show the Sprint-on-Verizon phone to our less technical friends though? They try doing the conversion then all of a sudden there's a swarm of people calling Verizon for support because their phone doesn't work or has other issues. Or people call Verizon saying their Sprint TV or other Sprint applications don't work. Then soon people will expect ALL sprint phones to be able to be converted to Verizon and flood Verizon with calls for support. Think of all the questions asked and answered just in this forum...some several times

. Verizon doesn't want to deal with that.
On another note, does anyone know if any converted phones have actually been intentionally disconnected by Verizon?
Mike