The "what's new" and "Activity stream links should be working correctly once again. It might take a little while for the data to fill in, but it should be working as expected now. it's set, I believe, to track the past 5 days activity and will update about every 10 minutes or so. If you leave the page open for a period of time it will automatically suspend the auto update and you'll need to reload the page to see any changes.
In other words, don't leave the page open.