args.bungie.org

Others have noted the multiple Macbeth quotes by Adjutant Reflex, and this has loosed a thought of mine over on the Unfiction forums I thought I'd share here too.

Shakespeare wrote his plays in iambic pentameter; it's non-rhyming poetry made from pairs of five-syllable clauses per line.

Gravemind speaks in iambic heptameter; it's non-rhyming poetry made from pairs of seven-syllable clauses per line.

Dunno about how relevant this will be (hence my parking this in "speculation") but it does hint at some interesting possibilities.

-- Steve hasn't felt any pricking of his thumbs yet, but will definitely pay attention if he does.

Actually, Gravemind speaks in trochaic heptameter. Seven groupings of two syllables, each with a stressed/unstressed pattern.
Iambic heptameter is the opposite stress pattern, seven groupings of two syllables, each with a unstressed/stressed pattern.
wikipedia
I wouldn't know this if it wasn't for Gravemind.

We are 99% sure that Gravemind does not have anything to do with this ARG at this point. And this subject has been discussed and discussed ad nauseum.

Keep thinking though.