Blogger is beginning to roll out its new user interface to users, one batch at a time. Previously, the new UI was only available by logging in to Blogger In Draft. I don't see too many differences between the final version and what I originally saw. And of course this doesn't affect the way your blog looks to its visitors, only the way Blogger looks to you when you're writing posts.
Over the last few months I've seen new versions of other Google products, such as Calendar, Docs, and of course Google+. Some I like, some I don't. Overall, Blogger's changes are an improvement, though I do think they went a little crazy with the whitespace.