I have been using your site for about a week now, and I like it.  Nice work.  I have a couple concerns though:

• I like the security that comes with no user accounts, but the network transaction speed sometimes introduces a significant delay between when I want my bet to be placed and when it actually gets placed.  It is most irritating when this happens.
• I keep running out of spendable BTC because it takes so long for my winnings to come back to my wallet, your txs take forever to get confirmed.  If you had accounts then I wouldn't have to wait and I would be able to place more bets in a day.
• It would be nice if your site would show me stats about how I'm doing.  Again, if you had user accounts then you could do this.
• You have no email/support information on your site.
• I'd like to see a countdown timer that shows how long until each bet is closed.
• I'd like to know where your price feeds come so I can see if you are manipulating them and screwing me over.

I had an issue today, the first one like this in the week I've been using your service, where I sent you three transfers of 0.3 BTC each but my bet never showed up and I never got anything back.  I did not win or lose, your system simply ate my BTC.  This is a very bad sign.  You have no contact info on your website anywhere so I am not able to contact you about this and find out where my 0.9 BTC went.  What happened to my coin?

I'll send you a PM to follow up on this missing coin.

UPDATE: They did return my funds today, it took 12 hours to get it back, so not too bad.