In Tales of the Fallen Issue 4, The Fallen specifically refers to the Dynasty of Primes as the Children of Primus... Yes, this may be an IDW only attribute, but the IDW comics are generally assumed to be at least 'partially' related to the full movie verse, if not fully canon. Spoiler This also makes things all the more confusing because this happens only a few pages after the Allspark supposedly speaks exclusively to the Fallen, throwing a twist that it may infact have connections to an 'evil' sentience, rather than just Primus! (Take a guess who that could be...) Will Primus appear in Transformers 3? I kind of doubt it, personally. But this is still a very notable event... Let the speculation begin.