The standing stones achievements reminded me of something... we've seen standing stones in Bloodmoon, which was close to, if not a part of Skyrim. Is that why they put standing stones in Skyrim? That would be awesome.
It seems so, yup -- the "Quest of Aevar Stone-Singer" stones, etc., which appear to be a Nordic thing. Solstheim is extremely close, geographically, to Skyrim proper, and we're currently seeing lots of interesting Bloodmoon nods and tie-ins recently.