Another vote for this. I find this whole thing a little crazy.
As recently as last month the PHP SDK was being promoted on your site (see https://web.archive.org/web/20160505032529/https://www.dropbox.com/developers/documentation). This was silently dropped, though the SDK itself remains hosted on the official Dropbox Github, and has been getting updates as of 5 days ago.
There are no doubt hundreds of apps rely on this, and as it stands they'll all cease to function in a year, unless we hack together our own API client. Note that many of those apps (including my own) are used every day by your paying customers, and in many cases are the reason why those customers pay you.
I'd be totally happy to help contribute to upgrading the current SDK to use v2, but there needs to be someone from Dropbox spearheading the project, even if it's just creating a new repo or branch for the updated version.
Please don't abandon your developer community!