*just opinion and speculation* This would essentially make SC and BTC nearly identical at least to an uneducated consumer as this breaks one of the nicer to see features ie. the difficulty algorithm ... from then on it would be a race for adoption (SC's speed enhancement to transactions gives it a plus here and BTC's current level of adoption gives it a plus here) and once the whole "green address" concept takes off it could hurt SC's speed effect but likely both would add the support but SC probably more natively... since that would then be mostly negated it's a race for pure fiat value.  At the moment (But changes tomorrow with Ruxum) to get SC you have to go through BTC but once they are both trading directly to fiat it will be the one that is more ideal to investors/speculators currently with no major mishaps SC is favorable here, but BTC already has a head start and with a few million less total coins SC has a slight value advantage, but this is negated somewhat because SC users have learned from the BTC mishaps that caused thousands if not more coins to be lost or those really early people who were just "playing" with BTC and have just left dead wallets so that advantage may be somewhat negated as well.

Merged mining between these currencies will likely result in a "battle royale" where one will eventually come out on top plummeting the other to nothingness... SC has the advantages of lessons learned, BTC has the advantages of head start so it could be interesting ... on the flip side if one or the other does not participate in merged mining that one would cease to exist rapidly because I can't see a case where miners wouldn't participate in merged mining to maximize profits among the several cryptocurrencies.