If you’re the nostalgic type who still has much of your office content stored in Microsoft binary formats, get ready for a busy weekend: the Chocolate Factory has decided that users of older Microsoft Office versions are an anachronism, and on Monday will kill off support for .doc, .xls and .ppt file formats.

The changes to Google Apps will apply to all editions.

The move is troublesome not only for stick-in-the-muds who haven’t upgraded their Office installs: it’s perfectly feasible that much of a large business’s corporate memory will be in the old binary formats (along with spreadsheets containing large, custom macros that nobody’s rewritten in the newer versions yet).

As BetaNews puts it, if you worked in Microsoft marketing, “October 1 would be champagne day, baby.” The move at the very least gives Redmond a gold-standard product differentiator: backwards compatibility.

Google Apps users now have only a handful of options: convert every document to the new .docx/.xlsx/.pptx formats before uploading them to Google; stick with Microsoft for backwards compatibility; or abandon both entirely in favour of something like LibreOffice.

The question now is whether Google presses ahead with the decision, or changes its mind in the face of an almost-certain outcry from users. ®