Good question. I think they would have liked to call it RSD version 3, in other words just an upgrade of RSD2.5. The way this new version was announced (before launching) was so that some of us, me among them, thought we would have to learn everything over again, and we feared that we could not go on using/updating the projects we had created. So we protested, and the staff listened. Therefore we can keep RSD and SD installed on the same system, we can even still download the last RSD version. Quite good service, actually!
It is a pity though, that the names are so similar, and also, that projects created with either of them have the same file extension, .rsd. You really need to keep your tounge straight when working with them.

Hey Inger does RSD come pre-loaded with any themes? or do all themes have to be purchased through the web store?

RSD comes with several themes and components. If you have version 2.x, the themes can be converted to be used in SD3 without too much trouble (well, they can be used without converting too, but then you will be dragging around a stack of 'dead meat'). I have tried converting themes from RSD 1.X too, but that is more complicated, especially if they were built with the 'coffeegrinder' system.

You said initially in this discussion that you actually have both RSD and SD, so then you should be able to find the themes and components there.

The theme shop does not offer much of those themes for RSD, so let's hope you have version 2.x

It's now December 23rd and the change log has still not been updated. What has changed? A request - could you update the Change Log at the same time as the release is made available please?

Hi Mike, the people here in the forums are users, not CC staffers. If you want to speak to a staff member, you need to submit a a support ticket.
We have asked the same question before, BTW...