SBF tested on Engineering ATRIX.
It is real, fast and reliable: it can be something like an internal Release Candidate for the Olympus, probably this is the version that will get signed and released to the end users.
Root is possible and has been done (not with gladroot) on my device.
NOTE: Don't attempt to flash it or you'll fail! It is signed with TEST keys. Mine is an unlocked engineering olympus!
In response to the above question: yes! Looks like we'll be getting 2.3.4 straight away. Dates will be announced soon-ish. We're getting verrryy close.