I'm the guy that makes these docks, so I will try to shed some light on it.
The older docks were made using older generation cables. They work with the iPhone 4 with no problems if you are not using a bumper. The problem with using them with a bumper is that the 30-pin connector on the dock is now too wide. It measures 6.7mm wide. The bumper has a recess molded into it at the 30-pin connector location that is only 5.8mm wide. Therefore the connector cannot fully insert into the phone. Sometimes if you press it down tight you can get a decent connection, but it is not reliable. The new iPhone 4 docks we offer use a newer cable that will fit inside the recess of the bumper.
As for offering a black anodized dock that will work with the iPhone 4... it appears that we have found a cable manufacturer that can provide us with black cables that have the thinner 30-pin connector. However, it will take us several weeks until we can offer it as a standard product. I would expect to have it on the website in about another month.
Finally, at this time we cannot make any guarantees about fitting any case from a third party vendor. There are still a lot of new cases coming out on the market and we haven't been able to test many yet. So for now, the only available option is if you have no case or a bumper. Any case that covers the back of the phone will probably not fit. We hope to offer additional sizes in another month or two.
Thanks.