While the gesture to Clipboard comes as some relief for Amplify's users, it's not expected to be a catch-all for existing clips that have been captured over the last few years. A blog post announcing the move says "We can't guarantee that all of your clips will be preserved", although databases will be transferred, and it's hoped a migration is possible. Of note, Clipboard, run by former Microsofties, has garnered praise of late from Michael Arrington and GeekWire.
A Note to Amplify Users By Email
While Amplify's note to users was short, Clipboard says Amplify "struggled for some time to continue operating. The reasons why are difficult to state, but ultimately neither service was meeting the needs of their user."
One user, Paul Simbeck-Hampson, wrote in detail on Google+, that Amplify "was a community of thoughtful considerate people who took time to engage, share and support one another around topics that were meaningful - it was like a grown ups meeting place," adding that even while discussions on curation and copyright flared up, Amplify made many changes to be on the right side of content owners.
Unfortunately, that effort looks not to have been enough. I appreciated the Amplify bookmarklet, especially on mobile, and think that sharing selectively on the web, having a discussion downstream with peers, is valuable - but this particular service didn't survive. You can see more on the Amplify site or on the Clipboard blog.
Disclosure: I work at Google on the Google+ team. Any conjecture as to whether this is good or bad for Google+ is trying too hard. :)