First of all I'd like to wish Matt and the guys the best of luck during this hard time; irregardless of how it happened, it's never fun to have your business touched like this.
About the situation: I have to assume that credit card details are stored encrypted, but decryptable. Otherwise recurring payments couldn't be made. You need the credit card details for that. Based on that assumption, I also have to assume that all credit card numbers will eventually be decrypted and possibly sold/used. So my advice is: cancel you credit card (and start paying with PayPal!).
I'm unsure how passwords are stored, but if it's plain md5, most of them will be decryptable by now. If it's salted md5 or sha1 (salted or not), I'm seeing less trouble. I've already changed my password, though, just to make sure.
About the hosting provider: I hope they're finished or at least hit hard by this. It's absolutely unacceptable for a hosting company to let this happen. It is *always* fishy if an administrator cannot find their details and can't recover them from the client area. It's even more suspicious if shortly after giving access, the e-mail address is changed and the login details sent. Hosting companies should be so much more careful with this.
Finally, I'd like to keep getting updates on this. Clear customer communication is extremely important in cases like this. So I really hope the current way of communication is set forth or even improved (more details!).