We all know not only that Ethereum's developer is Vitalik Buterin but even who is that guy, who are his parents, where was he born and where did he got his education, what are his points if view on different topics, etc. Does it impact on Ethereum? Of course! But does it make Ethereum unpopular because of having less mystery? I don't think so. So I don't think that revealing or not revealing of Satoshi's identity will impact of a future of Bitcoin significantly.