link
Once ESTA is mandatory and all
carriers are capable of receiving and
validating messages pertaining to the
traveler’s ESTA status as part of the
traveler’s boarding status, DHS will
eliminate the I–94W requirement.
That is different language to the earlier announcement and implies there may be a considerable period when both I94W and the ESTA have to be completed

Any bets on how long it takes some tinpot airline to comply?
Under ESTA, CBP also will be able to
screen travelers seeking to enter the
United States under VWP prior to their
arrival in the United States.
They already do screen VWP pax through the APIS data prior to arrival in USA (actually prior to departure from previous country visited).
Aliens
intending to travel under the VWP will
be able to obtain travel authorization in
advance of travel to the United States.
DHS notes that an authorization to
travel to the United States under ESTA
is not a determination that the alien
ultimately is admissible to the United
States.
So the reason for ESTA is to provide certainty to VWP pax who might otherwise arrive at USA and be denied, is just hot air.
ESTA will collect the same
information currently required on the
Form I–94W that is presented to a CBP
officer at a port of entry.
So we have to update for every flight number and address for every visit? Sometimes that info is not known 72 hours in advance.
Potential terrorists also may use VWP
exemption from the visa screening
process as a means to gain access to the
United States or an aircraft en route to
the United States to cause serious
damage, injury, or death in the United
States. Thus, implementation of this
rule prior to notice and comment is
necessary to protect the national
security of the United States and to
prevent potential terrorists from
exploiting VWP.
LOL - so just how many terrorists have exploited VWP to cause serious damage, injury, or death in the United States that would have been admitted under current rules and not admitted under this proposal?
changes to the Arrival and Departure
Record, Forms I–94 and I–94W. These
forms are in the process of being
updated under the Paperwork
Reduction Act.
So extra info can easily be added to I-94W before these are phased out and can still say the ESTA has not added to the data required of visitors
DHS has considered the
impact of this rule on small entities and
had determined that this rule will not
have a significant economic impact on
a substantial number of small entities.
So reduced visitor numbers due to the new rules, and the reduced spend / R&D / etc is not an impact?
There's several pages outlining their estimate of the costs and "benefits" of ESTA. The methodology used is very flawed.