I was devastated when Google announced the closure of Google Reader but honestly, I am all good now, for the most part. I switched happily to Feedly but keep in mind, there are many alternatives.
But now I learn that Google Reader's demise is also the demise of other Google products.
iGoogle Feed Gadgets
iGoogle Feed Gadgets all went offline yesterday when Google Reader shut down. A Google Web Search Help thread has many complaints from users and Google confirmed the issue. Jessica from Google said:
I'm sorry to hear that this is so frustrating for everyone. The feature was dependent on Google Reader, which was sunset yesterday. Unfortunately, this means that the feature isn't functional anymore.
Of course, iGoogle is closing down shortly as well.
Google Alerts RSS Delivery
Also, Google Alerts all of a sudden stopped supporting RSS as a delivery option. I depend on this feature, as I mentioned in my outcry on Google+.
If you look at my screen shot, you will notice the warning message "Google Reader is no longer available." So what, let me subscribe to it via another RSS reader!
Google should have also warned us about the collateral damage the closure of Google Reader would cause.
I am sure there are other examples of where Google Reader caused other Google services to fail.
Forum discussion at Google+ and Google Web Search Help.