Paul, of The Elders Tribune, has just introduced a new "Planet Elders" feature that makes it easy to discover blogs by and for seniors. He welcomes suggestions for new blogs to include, so recommend your favorites--or you own.
See the The Elders Tribune at http://elderstribune.com/. Click on "Planet" at the top of the page to find the list.
Unfortunately, The Elders Tribune and its News Aggregator are gone. The founder got a new job and moved overseas; he left the site up for while, but now it seems to be gone. I was sorry to see it go.
For now, the best listing of Senior Blogs I'm aware of can be found in the Elderblogger Blogroll on the left side of Ronni Bennett's "Time Goes By" at http://www.timegoesby.net/.