AWS actually isn't that bad when it comes to RSS feeds: Their official blog offers an RSS feed [1], but even better: each of their forum sections [2] offers a (quite hidden) RSS feed with all announcements in that section, which is quite handy if you're interested in news for a particular service only. For example here is the RSS feed for S3 announcements: https://forums.aws.amazon.com/rss/rssannounce.jspa?forumID=2...
[1]: http://feeds.feedburner.com/AmazonWebServicesBlog
[2]: https://forums.aws.amazon.com/