"People [are] starting to put the dreaded @ signs from Twitter in emails!"

That's a reader's report to Gawker:

Has anyone else noticed this trend (or is it a one-person trend piece?) From a reader: "People [are] starting to put the dreaded @ signs from Twitter in emails! Such as @Tricia, how did making that Excel spreadsheet go? and other horrible things of that nature." Has this infected your office as well?

It hasn't yet, but I think it's a brilliant convention to export for the same reason that it makes sense on Twitter: it allows you to set up automated scripts to identify direct addressees within the body of text. It also makes it easier for humans to scan text for direct address.