Not exactly conspiracy, but I believe this is relatively new as there isn't much on the net-YET-but no doubt this will take hold and generate more fear (al-a Planet Ex) and no doubt bucketfuls of bucks for the producers of the DVD:
http://www.thehorizonproject.com/
The new spin is that civilizations have come and gone before us leaving nary a trace because every (what is it- 26 million years?) the solar system passes through the galactic plane. I have looked into this notion before and can't seem to find a straight answer as to what effects on the solar system this will really have (perhaps bother a few asteroids and send them closer?), nor can I pin down when this "galactic crossing" will occur, but some claim it's already happened or or still yet to happen. Point is, this Horizon Project has a team of "scientists" and (not surprisingly as this is woo-woo land) "remote viewers" (somehow I feel Ed Dames might be behind this), are claiming that in the magical year of 2012 we will be smack dab in the middle of the clutches of the "gravitational waves" put forth by the galaxy's black hole which will cause the obligatory and long-predicted-by-just-about-everybody-crazy poleshift (magnetic or geographic they're not sure) which will ruin the planet, increase solar flares and influence our weather (they claim those last two things are evidence we are nearing the galactic center right now and things will get worse, of course). So, (sigh), I'm afraid that their website is about to generate momemtum and hysteria over the next few years and that is MY prediction! I don't know how credible their scientific backgrounds are but just reading the list of "resources"
http://www.thehorizonproject.com/thp_resources.cfm they cite Albert Einstein, Heisenberg right next to Nostradamus and Mother Shipton! Alrighty then..... Let's have fun with this one! --SORRY FOR THE DOUBLE-POSTING---MY BAD!---