I think the highlighted passages, while threatening, miss the real meat of this ruling.

All the facts and circumstances must be taken into account when assessing whether a link produces that result. The facts and circumstances to be considered include, but are not limited to, the context for the link on the organization’s web site, whether all candidates are represented, any exempt purpose served by offering the link, and the directness of the links between the organization’s web site and the web page that contains material favoring or opposing a candidate for public office.

They go on to give two scenarios where orgs link to candidate-related material without violating their exempt purpose: one is a voter guide that links to all known candidate sites and the other is when you link to an article relevant to your exempt purpose on a newspaper's site that also has editorials favoring candidates somewhere on the site. I read this to mean that if my organization, which is a nonprofit association of nonprofits, links to your article about the IRS ruling, to inform our members about the ruling, we're in the clear even if you proudly profess your support for Tom Tancredo elsewhere on the site. While the link path from the article to the pro-candidate content may be shorter on your site than on the MSM paper, I think the principle is the same.

In terms of the ominous bit about "Because the linked content may change over time..." I think the lesson to draw from that is to use what is smart linking behavior anyway. Don't link from your animal shelter's site to a dynamic home page on the day they're featuring cute puppies, because the next they may be featuring Cynthia McKinney for President. Avoiding the wrath of the IRS isn't the primary reason to avoid making that link, a desire to have your web site make some basic sense is. So link only to non-partisan content, and use permalinks and you're probably okay.

As far as user-generated comment, I am NOT an attorney, but it seems to this interested lay person that it's reasonable to expect that 47 U.S.C. sec. 230(c)(1) would apply here to protect nonprofits from liability for their users' posts and links. "No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider." This law has protected message boards from libel claims in the past, and seems directly relevant.

Finally - for all the fretting and accusing and finger-pointing from different organizations, the IRS just doesn't take 501(c)(3) status away capriciously. Only the most blatant of violations have resulted in loss of status. Certainly that's subject to change, and we all have an ethical and legal obligation to keep our organizations operating within the law. But I don't see anything in this ruling that makes me fret for the way my organization currently links to external content, and I'd encourage other organizations to think carefully about what's going to advance their mission before adopting a defensive or conservative policy based on this ruling.