The bit that throws me somewhat is that those are cheap and act as promotional materials - dreamland is probably the most expensive, but that got to do double-duty since they did screen it on television over Christmas, I believe, and they're selling it internationally on DVD; while these new episodes could easily be regarded as promotional materials, I find it hard to believe they're particularly cheap.
I mentioned it over on the gaming side that I'd convinced myself it was a BBC Worldwide venture, testing the waters for a more ambitious commercial project, but someone pointed out that that probably means that they couldn't promote it on bbc.co.uk, which is a very good point - so I'm back at square one.
Incidentally, since it's been mentioned over in Gaming but not here: Charles Cecil is, apparently, involved. That's got quite a bit of promise.
One other thing I think is significant: The release date. Content featuring both MS and KG, with releases *starting* at the *end* of the season; more confirmation that both are staying on? It could just be a Missing Adventures approach, of course.