Yes they need to be fresh and unposted online.
That being the case, however, how long would Heresy have exclusive rights to them? Could they be posted up elsewhere immediately after they get posted here? (not that I intend to do so, just clarifying guidelines. Though if I were, I would certainly link back to Heresy as the article's primary source).
Additionally, how are large, multi-part tacticas treated? I have a serialized CSM tactica I've been meaning to complete, for instance, and though it's one thread, it addresses different subjects with enough content to justify a thread to themselves. I realize this is a fine line to walk, and may well have to be taken on a case-by-case basis, but it's a thought. (and as a minor digression, I realize that so far my CSM tactica has mostly been unit overviews of the type that don't qualify by these guidelines, but the next several sections I intend to post are broader articles on list-building, ally synergy, and the like, so they might well)
I will state for the record that I wholly intend to write articles in this vein, and this might well be the kick in the rump that will get me moving. Furthermore, (in my case, at least) if any of my articles should qualify for compensation, I'd rather that I wasn't paid in cash, but rather that my Supporter subscription should be extended by however much the earnings would qualify me for.