On first impressions, Creator is meant to be a Web application development tool, from the looks of it. There's no mention of distributed APIs outside of the servlet environment and web services, although Web services do seem to be pretty deeply integrated. Further, the kind of Web applications it's designed to create are, specifically, JSF applications.
This is good and bad. I'm not a proponent of JSF, yet, because I can see horrible, horrible things from it. Sun apparently sees it as a competitor to MS' WebForms, which to me sounds like they're trying to compete against something that just isn't that good, in someone else's arena. However, it's technology people at Sun are pushing, hard, and that means - for better or for worse - we're probably stuck with it for a while.
Creator's JSF focus is really not that bad. It definitely makes using JSF as simple as its proponents have promised - no longer are you rushing from element to element trying to get interactions configured. Navigation seems to be fairly easy to get right, although I've not yet seen (or developed) complex navigation systems yet.
The initial documentation is very, very simple. As this is an early access release, that's okay. The docs gave me an idea of what could be done, which is enough. I haven't seen any kind of portal or portlet integration yet, although maybe I'm not looking at it the right way.
The standard deployment environment is Sun's App Server 8. This is amusing, in a way - AS8 is a huge, huge package, with all kinds of capabilities, and using it as the deployment environment is overkill in a big, big way. It's also very slow to start and deploy with - and for a development environment, this is not good. You want something like Orion for this, with its second-long deployment of applications - not a fifteen-second deployment cycle.
Plus, TDD seems to fall by the wayside. I'm waiting to see what Dan North, et al, think of this stuff, because there is no test cycle for it.
Overall, the environment itself feels like an early access release. It's a great initial stab at questionable technology. That said, maybe that's enough to build some serious momentum - which will make the technology worthwhile, in a positive feedback loop. I don't know that I'm ready to use it personally yet, because I haven't seen how to do some of the things I want to do in the environment itself yet - it looks like it's good for JSF development, and barely okay for Java development - it's doable, but not really actively good.
So far, it looks like a standalone version of something that should be a plugin for NetBeans and, given the JSR for IDE plugins, other editors as well. (I'm drooling at the thought of something like this in IDEA, for example.) We'll see how it goes, and I'll keep playing with it.