I'm a serial apt-getter (running it often throughout the day), and I find it a great way to see where Ubuntu developers are most active. That being said, an RSS feed would probably be a smarter/safer way to keep up on what packages are being updated and when.
There was one, but it has since been discontinued until further notice. If you want to follow security notices though (I know not exactly the same, but still useful), you can add the feed from here: http://www.ubuntu.com/usn
Try these feeds (may not provide anything):
What about something like
http://packages.ubuntu.com/natty/newpkg?format=rss for all natty updates