This seems to be part of their new initiative - Google+, as they start to integrate their products to socialize user experience (trying to give Google+ a user boost in the process)
- Blogger can be integrated with your Google+ account, where posts are shared automatically.
- This sleek new theme is one change, breaking out from the old blog themes. The new dynamic view plays with the layout to allow users to sift through blog posts easily.
- Blogs are mobile enabled, having mobile themes catered to mobile phones
- Some of the newer themes do not allow for flexible customization from the old blogger, where the drag and drop modules let users easily add features to their blog.
Overall, Google's Blogger seems to be much cooler than before. Comparing it with wordpress would be another story for another time though...