When Google kills Gmail

This is good advice in general, regardless of which email service you use. Even further, it's good advice for any service you use that has a public component. I love tumblr, but if they were to go out of business tomorrow then foobar.tumblr.com isn't going to mean much. If you're using it as the backend for a blog at your own URL though, you can switch services without requiring your readers to change their habits. Whether it's email, blogging, or anything else, I think maintaining control of the entry point(s) for any publicly facing services you use is really important.

1) Google kills of Groups in favour of Google+ 2) If not (1), Google limits Groups postings to only those coming from a Google account. 3) Google kills off one or all of Sites, Offers, Finance, Blogger

Of those, I reckon (1) or (2) is the most likely. Groups (despite being really useful) was already out of date when it was launched.

Of course, that's all meaningless speculation like much of the linked article.

The conclusion at the end though (switching to an email account on your own domain), is relatively sensible (even if Google isn't about to close Gmail (hint: they aren't)). Controlling your own email address, if not the provider, reduces lock in and makes it generally a lot easier to switch to someone else in the future if/when something better turns up.