Which Email Clients Support CSS3?

Which Email Clients Support CSS3?:

With the current minimal support for CSS3 in most email clients, the easy counter-argument here is typically, "Why bother?" But I share the same views as Ros Hodgekiss, who authored the article:

Finally, just as many of the properties we have tested are considered to be experimental, we encourage you to be experimental, too. As more email clients join the fray, CSS3's applications in email will certainly become wider-reaching than pretty shadows and...