We've been beta-testing Sandvox for several weeks now with a small group of testers. We plan on opening up the beta program later to the many who have signed up, but the reality is that it's much more overhead to manage hundreds of beta testers than a few dozen, and that overhead would result in delaying the product, rather than bringing it on sooner.
In the meantime, we have fixed some great bugs (we've focused on the crashers first, of course) and solved some usability problems. We have solved some real "doozies." One thing we are discovering is that Apple's Core Data technology that we are using, although extremely powerful, is also extremely delicate. We have to go over a lot of pieces of the program with a fine-tooth comb to deal with these issues, so that Sandvox is rock-solid, not delicate!
We've also made great strides in integrating the payment/licensing section of the program, and the back-end components to support it. (Built in PHP, if anybody is wondering.)
We've started to bundle a recent build of Apple's WebKit (the technology that powers Safari) with the program. Even with the improvements released in Mac OS X 10.4.3, there are still several bugs which have been fixed in newer versions of WebKit that we need to take advantage of. The unfortunate side-effect of all this is that this makes the downloadable application rather large — over nine megabytes, compressed! On the bright side, when Apple releases their next update to WebKit, we should be able to stop bundling WebKit and give Sandvox a diet.
We know from all the emails and comments submitted here on the website that a lot of people are anxious to try and test and use Sandvox... we hear you! I'm reminded of the old Orson Welles commercial… We will release no software before its time. :-)