Google may be working on a significant redesign for Google+ though it's most likely going to be just an update on the existing layout and elements. There's not much to go on, but there seems to be a slow trend toward an updated look, with sharper graphics and corners.
For now, there's a new Google+ logo on the official Google+ page. An updated logo is also visible on the Google+ Developers page. The site's favicon hasn't been updated yet, but it should be soon. The logo is already used by the Android app.
Hints at a wider redesign come in the form of new features rolled out recently. They all look like they belong in Google+ and should feel familiar, yet they also have some new elements not found in the Google+ redesign unveiled last spring.
Google has long been criticized for its minimalistic and utilitarian design and, while the latest sites and apps are certainly minimalistic, they're also beautiful. You can thank Larry Page for that.