The most obvious change is the new yellow/orange logo, I do like it. But the main changes they want to highlight are the search features they've modified.
The Bing home page is now more "modern" in this new design, making it "faster, cleaner and more visually appealing," said Bing. Here are screen shots of how the new home page and search results page may look when it launches over the next week or so:
Here is a short video from Bing on the changes:
Bing also improved their "Snapshots" to include both place and people knowledge data into one.
"Page Zero" lets you search and see results without actually going to the search results page. Specifically, we covered a preview of this spotted in an alpha beta, which we called deep links in search box but obviously Bing calls it "Page Zero." Here is a picture:
Bing will also show a horizontal "pole" of information when they deem it useful:
Plus, this experience will work flawlessly on any device. From desktop, to tablet, to mobile to TV, it will be a beautiful experience according to Microsoft.
More on this announcement can be found on Techmeme.
Forum discussion at WebmasterWorld.