Also read my earlier blog about another Google Search layout.
Differences between the other one and this one are plentiful, and I'm glad to see that they have gotten back to the darker blue link colour. Light was too fuzzy ;).
Perhaps the biggest difference is that, even though I'm logged in with an Apps account that doesn't have a Google Profile, it showed me the +1 icons at search results. So perhaps there's a change coming there as well. One thing I do know for sure is that Plus One is coming to AdWords - that I just got an email about.
Update: And then suddenly it was gone... Google just shows me the old layout again, those b****ds ;). Just Google Maps shows me something that reminds of the layout I just got served. Oh well, let's see if this one sticks.
Update 2 (30 jun): This update seems to be rather connected to Google's (private, invite only) release of their Google+ Project. The demo screens of Google's "social network" at least do remind a lot of the new layout they presented me. Exciting!