Just thought I'd chime in with a few comments of my own...
Having seen quite a few websites around, I think a very critical part is to "sell" your product up-front. It's always good to have a page with details on Xoops, but the front page really, really needs to highlight critical features. You must ask yourself "As a complete neophyte to this CMS, why would I choose XOOPS over another solution?". You need to define what makes XOOPS unique/better and capitalize on this. With the little time I've had to work on it, I can say it's very customizable and the code is surprisingly clear once you get a hang of it. You can also highlight that it's modern thanks to its OOP foundation, that it has a lot of very professional modules, etc. The point is that the front page must be there to sell XOOPS first and foremost.
But at the same time, I understand Xoops.org is also a community site. It's used for development, news, etc. Hence, I think a good way of catering to both the newbies and the more familiar audience, you need to have a very flexible design: one that changes when the user is logged in. I think it makes sense! Not logged users mainly want to learn about Xoops, they want to weight what are its benefits and advantages. Once you've made an account, it's most likely because you want to contribute to the community or because you have a problem with Xoops. Either way, you are looking to get involved in the community aspect, hence you no more need all the marketing speech and you can either completely deal away with it or move it to a less important area.
For instance, you could make something akin to
ExpressionEngine's site for anonymous users (maybe put news down the page and such as that site feels a bit too business-y and not enough community-ran), and then remove the whole blue block when you log in. Don't need it, don't have it.
On another note, I noticed there might be something else you can do: SEO. I've seen some talks about it, but, without wanting to criticize at all (I think XOOPS is already a great project), you really have to do more about it. Just search for "CMS" on Google; Drupal comes nearly on top. I've yet to find XOOPS though... Which means you probably have great SEO for Xoops, but not so much for CMS. Unfortunately, you need to remember that people will look for CMS, Content Management System and other such keywords. People who'd search for XOOPS already know about it and want to use it, they don't need to be convinced. Plus, Google doesn't have too much trouble matching "xoops.org" with XOOPS in searches, so you don't need to optimize your site all that much. Heck, simple changes like adding "Xoops Content Management System CMS" to the title of all your pages might already help tremendously.
Those are the two main thoughts that crossed my mind right now. I really hope you keep on growing and make a killer site - looking at the designs, I think I shouldn't be worried about that
