I don't know if it's been brought up yet, but there's been a bunch of hidden stuff up on http://c0da.es, with a new message with a bunch of links in it popping up every half hour. I'll dump the links I found, and feel free to leave your own. Don't know what any of it means yet.
http://mythicdawn.es/clock.html
http://aurbis.c0da.es/s/p.png
http://c0da.es/#6c031d1fac6b0462214f32b1e34bfa5e (this one appears to be the same site, but with a long string of numbers attached to the URL)
http://c0da.es/#TRANSPOSE_OM_DABNI_SNOGIB_A_MAERDX (message in URL)
http://aurbis.c0da.es/s/e.mp3
http://aurbis.c0da.es/s/d.png
http://aurbis.c0da.es/s/f.png
http://mythicdawn.es/e.html
I don't actually have the messages, so hopefully someone can provide those. The most recent was "WOULDN'T WANT SECONDARY VISIONS" (1:30 UTC)
2:30 UTC- Art replaced, message changed to "TOMORROWIND, TODAY", linking to http://michaelkirkbride.tumblr.com/post/76587014026/submit-your-own-personal-c0da-to-tomorrowind
Original "NEXT CHECKPOINT: " text changed to "TEMPORAL ANOMALY: NEXT CHECKPOINT: "
3:00 UTC- New message is "THE DIGITALS KNOW NOW" and links to http://michaelkirkbride.tumblr.com/post/76587014026/submit-your-own-personal-c0da-to-tomorrowind and http://aurbis.c0da.es/s/u.png are hidden there.
The "TEMPORAL ANOMALY: NEXT CHECKPOINT: " text has been replaced with "NEXT CHECKPOINT: 3:30 UTC. ON. THE. CLOCK."
3:30 UTC- New message is "GVBFP OTWXD ZYHZZ KVWOL BWWDA XEIOR NHOKF ATSPB FAXQT SWBRL" Hidden in this message are links to http://aurbis.c0da.es/s/u.png and http://michaelkirkbride.tumblr.com/post/76587014026/submit-your-own-personal-c0da-to-tomorrowind
The text "NEXT CHECKPOINT: 3:30 UTC. ON.THE. CLOCK." has been changed to "NEXT CHECKPOINT: 4:00 UTC. THE DIGITALS KNOW NOW." Hidden in that text is a link to http://mythicdawn.es/clock.html. That link shows a strange image and the text "Qrnq ynathntr byq zrnavat".
4:00 UTC- New message is "I AM A FREE ASSOCIATE". Hidden in the message is http://aurbis.c0da.es/s/u.png and http://michaelkirkbride.tumblr.com/post/76587014026/submit-your-own-personal-c0da-to-tomorrowind
The next checkpoint is set to 12:30 UTC. See ya tomorrowind, everybody.
EDIT: Of note is that the next checkpoint is after the countdown finishes. Thanks, Savvblonk.
4:30- THOSE DIRTY LIARS. The new message is "THE WHEEL AS--" and it hides two links: http://aurbis.c0da.es/s/i.png and http://mythicdawn.es/clock.html
5:00- Message is now "CARRYING THE TIBROLS ON OUR BACKS TOGETHER AND CUTTING TUNNELS BY THE LIGHT AND HEAT THAT ALL MER WORE". The whole message was a link to http://aurbis.c0da.es/s/i.png
The checkpoint text has been changed back to "NEXT CHECKPOINT".
5:30- Message is now "HIS NAME IS ALANDRO SUL". Links to http://aurbis.c0da.es/s/j.png
The checkpoint text links to http://aurbis.c0da.es/s/i.png
6:00- Message is now "TAM! RUGH!" and links to http://aurbis.c0da.es/s/k.jpg and http://aurbis.c0da.es/c0da/s/sul.jpg
Checkpoint text links to http://aurbis.c0da.es/s/j.png and http://aurbis.c0da.es/s/i.png