You can do whatever you want to your own version of WordPress, and if it is really "cool", then post a link here to it on your site or consider adding the information to the Codex for consideration for addition.
That's the joy of Open Source. And if you brag about it enough, and people love it enough...who knows what may happen.
What specific mods are you thinking of making, out of curiosity? I would LOVE to figure out how to to list more than 15 posts at a time and instead of just the date and search, add a drop down menu for setting the order of the posts by category. Oh, and another thing, I'd add the post-slugs so I can easily see the name of the posts, helping me not reproduce them as well as making it easier to add a link to them by their permalink name.
That's a few of ~~my~~ ideas of a good time on the admin panels.