I could see an embedded Google Maps in Google Reader... for me, it's new. maybe i didn't spot it before.
Ex: see the last post on Ogle Earth here:
http://www.google.com/reader/view/feed/http%3A%2F%2Fwww.ogleearth.com%2Fatom.xml

In my opinion it's old!

It may be a little old, but I just noticed it recently too.