WPCandy recently posted an interesting article called 30+ Things That Should Be Changed in WordPress 2.6. It’s essentially a big ideas list spanning the administration, the comment system, and more.
While I don’t agree with all the statements made (for example, I, unlike the post’s author, think that WordPress MU handles multiple blogs wonderfully), there are a lot of good ideas. I particularly like idea #15, a “theme library API”:
With an API, “premium” theme websites, such as WPDesigner’s Theme Club, PremiumThemes.net, and iThemes.com can let subscribers add their site to the WordPress admin for quick browsing of awesome themes.
Cool!
I might also incorporate an idea or two into a future version of WordPress Tweaks.

Not a bad list but its very specific to what that user wants and not the wordpress community, i agree we should be able to customize wordpress a little more but for the majority of people what wordpress gives you is enough.