MS no longer supporting older file formats

I was going through my RSS feeds, and I found this article from Wired. Apparently Microsoft has decided to discontinue support for old MS Office file formats, but they don't provide a list of formats that are no longer supported. I completely agree with Wired's assessment:

While it’s easy for the casual user to dismiss this sort of break in backwards compatibility since it’s unlikely they have many key documents in older formats, there’s some understandably upset folks who have to maintain legacy documents in large corporate and academic networks.

Even if you are a casual user, you should be irritated by this development. If your files are in an old format, it becomes a pain to update them. Why should you invest in a system that may not be there for you one day?

Personally, I use paper, plain text, LaTeX, and openly documented formats (like OpenDocument, even thought I can't stand word processors and I think my graphic design friends would back me up on this one). None of these formats will become obsolete and so it makes sense investing your time in these systems. It looks like Wired agrees with me on ODF:

Naturally, there’s an alternative which is somewhat easier (and free): just grab a copy of OpenOffice which can handle the older file formats. Once you’ve got them open, now might be a good time to convert them to ODF documents lest Office 2017 decide to again disable support for older file formats.

Now if only Apple would include OpenDocument support in iWork, I would be much happier. It is already supported elsewhere.