We need "new" at the moment because ASICs are taking over the mining of scrypt coins. There's only a few options currently available for GPU miners, and those options are pretty fucking terrible. There's plenty of technical changes to be done still, but it's all pointless if it comes with a massive premine. I have a big enough set of rigs that I don't give a shit about getting premine -- just having a decent coin to mine is reward enough for me.
PPC, IXC and a couple of other old SHA coins are doing well however they are all ASIC mined. If we accept your logic all of these coins should be dead by now. As markm used to say (scrypt) ASICs can provide a solid and reliable network for many alts. So I'm not sure if we are really desperately need any new wundercoin. But I'm more of a(n amateur) trader than a miner.