Here are a few of my concerns:

a) There is no richlist available to my knowledge.  We have no idea how many people were privy to the inside information that Just-dice was going to solely feature clams and we have no idea how many coins the top holders have and/or what their intentions are for the coin either.

b) People are being asked to copy and paste their private key into a PUBLIC chatroom.  It's not hard to believe that users will not understand the instructions, mistype and reveal their private keys openly with funds still inside of them.  This is not OK.  Dooglus seems to get away with it because he has a spotless record, but what if this becomes common practice in the bitcoin gaming scene?  Scamming gaming operators will have a field day!  Please be EXTREMELY cautious and protective with your private keys!!!!

c) There is no way to tell at this moment what will happen when Clams inevitably gets paired with FIAT.  Will Just-dice close down and then it becomes a free for all sell off of clams?  How can we accurately speculate the stability of Clams?  The order book is extremely thin right now.  There are several hypothetical situations that do not play out well for users if they buy-in heavily into clams.

Final thoughts:

Just-dice has always been a great reputable site ran by a very competent and trustworthy operator (Dooglus), but I highly suggest that users do not gamble for high amounts of bitcoin value as there's many unanswered questions and high levels of risk.

If you want to play for fun, mess around with a trusted gaming site, and are not too concerned with financial risk, then by all means I think Just-dice is one of the best places for this.