Lol, developers don't do sneak launches because they are worried about a 51% attack. And they don't use Scrypt to stop the democratic process?
WTH. It's scary when a "Developer" doesn't even have the basics down.
Anyways to explain the 51% attack to the other guy who asked, in newbie speak, since I am a newbie as well, and not someone that could actually pull off an attack. With a PoW (Proof of Work) currency, Your network is running on a democratic system, where if someone tries to attack the coin (By changing the Blockchain allowing them to double spend coins ect), the network looks at the 2 different Blockchains, and awards the chain with the majority of the Work being completed on it as the correct one, and all the other computers in the network will then adopt that Blockchain as the real one.
SHA256d, Scrypt, SHA3, Finding prime numbers. All that doesn't really matter to the "Security" of the Blockchain. The Blockchain isn't actually super-encrypted, it is open for everyone to view it at will. What all the computers on the network (mining) for your coin are doing is proving they are completing work, as a way to give themselves a small % of the total amount of voting shares for which chain is the correct one.
When a network has a small amount of miners, (you can see many with around 1 Mhash/s), all it would take is for 1 person with 1.1 MHash/s to start mining, and by all rights, they can start selling their coins (get the money), put them back in their wallet, spend them again, and again and again. Once this happens, the coin is pretty much worthless, and it falls to obscurity. With a larger coin with say 200 MHash/s on the network. They would need the processing power to put another 204 MHash/s on the network to attack it. But what they will usually do is look for weaknesses like a certain pool has 50% of the hashing power, or 2-3 large pools, and DDOS attack the pools effectively shutting them down for a period of time. During that time the network may be floating around the 40-50 MHash/s rate, thus it would be possible for them to attack the coin if they had the hashing power.
This is where some people believe Scrypt networks are more secure, as the price of creating a GPU farm with 50 MHash/s is more expensive than buying a few ASIC miners and having alot of power to throw around. As more ASIC's are being shipped out to people all over the network, this problem will dissipate. Not saying anyone could easily afford to take down Bitcoin. But if you had your new coin launched, on SHA256 and the network was being mined at even 100 G Hash/s, it really wouldn't take much at all to find someone that has the power to knock your coin out.
What a PoS / PoW currency does (Like PPCoin, NovaCoin, Bottlecaps) does is not only does it look to see if the attacker has 51% of all the work being completed on the network. It also checks to see if the attacker owns 51% of all the coin days on the network. This vastly makes it more expensive to attack, and would be financial suicide, as they would never be able to sell off all the coins they owned in the currency during the attack. So they would effectively lose money attacking it. With a strict PoW system, if they destroy it, they still have all their original equipment, and can go destroy the next coin they feel like, or go back to mining their favorites again.
The greatest thing about a PoS currency, is after the PoW is at the end of it's lifecycle, the network can be switched over to a total PoS security. The amount of electricity being consumed to keep the network secure drops to almost nothing, as all it is looking for is 51% ownership of all the coindays on the network to provide the security