Official decisions are yet to be made but a recent entry in Tim Bray's blog indicates that momentum has quickly materialized and this is the direction its heading.
According to Tim, "Sam Ruby is charging ahead with the idea of taking Atom to the IETF, and I generally approve.""I think Sam and I and Sam’s employer and mine are all in about the same place on this; with little investment in what the tags end up being. On the other hand, a lot of us are convinced that getting a format and an API written down cleanly and in one place and with some process around it will help the whole industry to grow faster; and help the software to be generally a little better. Which can’t be a bad thing", says Tim.
Read the lively discussion
transpiring on Sam's blog.