We are 5 devs working on the code, at launch one of them looked the part of the address but since he's not used to Base58 encoding he checked https://en.bitcoin.it/wiki/Base58Check_encoding and thought 25 would be S. Remember we are multiple devs working on the code.
Regarding your coment cryptodevil, how can you say the first letter of the public key is the engine ?

We discovered it pretty soon, but what implication does this have? None. On the other hand would you really think it would be a good idea to change the address formatting after launch? No.
Anyway, how can anyone call this a problem? We have bigger problems to deal with, and if this is the only criticism you can make over Silk, well we're happy.

On other news, seeing the last nights dumps we will try to include the built-in exchanger in tomorrow's update to boost up confidence a bit in the market.
We are also trying our best to finish the revision of the paper as soon as possible. I hope you still liked the present released infos .

Last thing, we are thinking about moving the thread to a self-mod thread. I was against that idea at first but seeing it's becoming impossible to have a civilized discussion/debate here because of the FUD & co we feel this our only option.