eMunie is not a scam. I've seen their client and it is remarkably stable and complete. It has been in development and testing for over 8 months and will launch an open beta this week. If the founders have a scam in mind, they wouldn't have put so much effort in it.

ethereum is founded by Vitalik buterin, who has been writing very thought out articles about bitcoin with a high sense of ethics for over a year or two. Even though ethereum has been under development for only 2 months (still longer than most scamcoins), I simply trust ethereum based on the founders' reputation.
The goldman sachs thing sounds a bit too tin-foil-hat conspiracy to me.