This one snuck in...

 - debugging message for ACPI

 - Intel guys removed it from their 2.4 tree (at my request)

 - it's point-in-time specific (message becomes nearly useless after
   ACPI bug fixes)

 - b/c of the point-in-time issue, it's IMO much more appropriate for a
   vendor kernel (where the message, I agree, may be helpful)

 - can potentially mislead users to the correct cause of root mount failure

 - overall, I disagree with adding messages like this.  The number one
   bug report, by far, for networking drivers is ACPI-related (no
   interrupts delivered).  You don't see me adding "boot with acpi=off"
   messages to the net subsystem.