I'd love to see the best of both worlds. I too love it when someone takes the time to summarize an article -- great community service. I'd love to establish a convention for doing so (I vote for prepending "Summary:" -- I find "tl;dr" irksome).
Then HNsummaries.com could fetch those when available instead of or in addition to the auto-summaries.
Funny, I created exactly that few years ago, got some traction and a story on readwriteweb.com, and then let the app stagnate and die. Maybe I should pursue it again :)
Then HNsummaries.com could fetch those when available instead of or in addition to the auto-summaries.