Vertcoin comes with Adaptive-N-factor, which means the scrypt algorithm PBKDF parameter
N will be changed according to the announced time table. Litecoin has
N=10, while Vertcoin starts with
N=11. And they claim the adaptive-N will resist the ASIC miner.
To produce an ASIC produce, it will need a huge amount of initial cost because of the prototyping (FPGA), HDL design, emulation, synthesis and layout, wafer fabrication, packing, and testing.
However, scrypt ASIC is now a real product (no matter how much it costs now). So re-target it to another new parameter should be not too difficult. I mean the whole architecture does not change (PBKDF is the same; only some parameters change, such as memory size and
N), so the new ASIC development won't need to be started from the scratch up, such that cost is relative smaller than the initial product started from ground zero. Moreover, at the time of
N adjustment at Jan 2016, the transistor size will be smaller and memory speed will be much higher, new technology will also enable the realization of the new ASIC miners for the new
If CPU/GPU can do the scrypt adaptive-N-factor algorithm at that time, I can say ASIC can also do that if there is a market and lots of demands. My idea is that, if vertcoin is very profitable (like or surpass BTC), Those ASIC company would also love to produce their ASIC miners with new N-factor. They could produce scrypt N=12 miner ready for the N-factor changes at Jan 2016, and announce for the pre-sale 3 or 6 months ago.
To me, adaptive-N-factor is just like one of BTC difficulty things. No one is mining BTC with miners whose hashrate is MHs or 10GHs or below, although all BTC miners are using the same proof-of-work algorithm