There will certainly be profit taking.
But that has happened on every coin during valuation revisions. The amount of profit taking that goes on depends on the long term viability of the asset. The money doesn't just come out of this coin - it's got to go into another that the holder thinks will be more profitable. On the other hand, if they think this one is, it'll stay in.
Originals are originals. Once they acquire a dominant market position it's very difficult to shake them loose. They certainly don't get shaken loose by clones that improve on the technology. Look at:
Bitcoin
Peercoin
Litecoin
NXT
All of these are top 10 market caps which have existing competitors or impending ones which are way more advanced in their technology sector.
Yet it doesn't do jack to their valuations.
That's because there are socio-economc reasons for their persistence which are way more powerful than improved or copied technology. For a start, once the majority of the market's invested in something, they need a damn good reason to go through the whole painful process to de-invest and re-invest in an untried competitor who's ultimate valuation is a complete unknown. The market wants safety. It doesn't care about better technology once it's found one that "works".
How many "coins" have copied Bitcoin's source code ? How many coins have Bitcoin's valuation ?
How many "coins" have copied Litecoin's source code ? How many coins have Litecoin's valuation ?
Also, as the dev of this coin stated earlier in this thread. "Are they going to clone me ?". And that is a very relevant point, because he is a known quantity who has established a record of technical competence and delivery that probably outweighs any marginal technical advantages that a competitor might come up with.
Also, it has now been stated that so called "signature coins" are on the RC3 roadmap for Darkcoin. That just about hammers the final nail in the coffin for any prospective competitive threat for me - in the medium term at least.
Just sayin. You can't ignore facts in front of your face. (At least I can't ).