I'd say the only people really against this right now are ASIC owners. Sucks for them but 'securing the blockchain' is really just fancy speak for trying to hold a monopoly on hashing power and screw the little guy. A BTC fork to scrypt has been discussed for a while now and was even recommended by the guy who made the BTC hashcash algo. There is very good reason to do this unless you WANT the future of BTC to be in the hands of ASICS.

In my opinion one of the major reasons litecoin and the alts have gained so much traction IS the ASIC problem BTC has now.