WordPress officially announced in their blog today that WordPress 3.1 will include the following features:
1. Easier Internal Linking:
With the new internal linking feature, you can now enter any URL to create a link just like you used to, OR you can search your existing posts and pages right there in the link popup. A combination of pre-loading, autocomplete, and some ajaxy goodness make the new link creation tool a joy to use (and man, that popup is so much faster!). This addition spurs you to make more connections between pieces of content on your site, which will make it easier for your visitors to find more related content from you.
2. Column Sorting:
Posts section (or Pages, Media, any screen with one of those listing tables), can now be sort by date, alphabetically, by author, or other criteria.
3. Better Pagination:
If you have a lot of content, with the new pagination style, those quick forward/back and first/last links are still there, but now you can jump right to any screen by just changing the editable number shown in the pagination area (and hitting enter).
4. Ajax Search Results:
Reviewing search results will be faster and no longer require screen refreshes in the dashboard, thanks to the addition of ajax to the search results screen.