Yep, long-time OE users are going to be faced with a decision that might be perplexing for some of them. They have a lot of clients from which to choose. I suspect Windows Live Mail may have a bit of the upper hand just because it's from Microsoft but we'll see.
Of the 11 clients covered in the article, I'm familiar with three but mainly with Windows Live Mail which I installed soon after getting Windows 7. The other two are Mozilla Thunderbird and Opera's email client. I could live with any of them but they're different. So, some users may want to try more than one to compare them.