The one thing WordPress is really weak at is structuring its content, by default it wants to shove everything into one big list of posts and allow the user to organize it using categories and queries etc. This works fine if your site is just a blog type site. But if you have multiple areas for example say a Blog and Portfolio and need two areas, things become more complicated and very un-elegant.
For example to create a blog and portfolio I would need to create two categories and then style up the category page to look like sections but then these would still only be categories of the main site (domain.com/category/blog/) which isn't ideal. Yes you can remove the category prefix but what about archives? They will still be relative to the main site (domain.com/2010/) and what if you wanted a page within your section for example (domain.com/portfolio/hireme) you would either have to create a page called portfolio and add in the query into the template but this means you'd have two pages acting as portfolio, or you could fake the permalink but both are hacks no matter how you swing it.
The proposal? Sections!
So you'd have your default section which you can't delete this is essentially what we have now and would be adequate for most sites. But for those that say want a Blog and Portfolio they could create new sections called that. Then they could assign there categories to those sections and that would be all. No templates would be needed as the sections would be purely structure based and not change anything about the way WordPress currently works.
Using this new system you could for example have the following structures:
As you can see everything works pretty much the same except by using Sections we get these nice prefixes to structure our content better. But this is much more than just pretty urls. This would be useful backend as you could assign pages and categories to sections thus more efficient.
Hopefully this is something that can be developed into 3.5?
Would love to hear some thoughts...