NHC and RECON are now reporting Earl's pressure at 978 mb. This is an 8 mb drop in less than 6 hours.

With such a large wind field it will take Earl several hours to convert the pressure drop to an increase in wind speed.
Recent Vortex messages are indicating a opening in the Eyewall further reducing Earl's capability of a rapid increase in wind speeds.

All interests in the Northern Leeward Islands, US and British Virgin Islands particularly St Maarten and Puerto Rico should consult their local weather service and take heed of any Watches and Warnings.

Persons in the Turks and Caicos Islands should monitor Hurricane Earl very closely as the storm could pass over or very close to the Turks and Caicos should the current track play out.
Earl is expected to begin a gradual turn to the northwest in the next 2 to 3 days, per the latest NHC Advisory.

Also of interest is the remarks section of the latest Vortex.
"Remarks Section - Additional Remarks...
MOAT 8NM WIDE CENTERED 16NM RADIUS AROUND EYE NW THRU EAST"

Is this the beginning of an eyewall replacement cycle? Moats are rarely reported.

http://www.google.com/search?hl=en&source=hp&q=hurricane+moat&btnG=Google+Search

http://www.aoml.noaa.gov/hrd/tcfaq/A12.html

Edited vortex messages from today First and Latest.
URNT12 KNHC 291233
VORTEX DATA MESSAGE AL072010
A. 29/11:48:50Z.............. 7:48 AM EDT
B. 17 deg 07 min N
057 deg 41 min W
D. 45 kt...surface wind speed estimate
H. 986 mb
L. OPEN SW-NE
M. C20 naut miles eye diameter
MAX OUTBOUND AND MAX FL WIND 81 KT NE QUAD 12:07:30Z

URNT12 KNHC 291738
VORTEX DATA MESSAGE AL072010
A. 29/17:21:40Z................. 1:21PM EDT
B. 17 deg 22 min N
058 deg 47 min W
D. 65 kt...surface wind speed estimate
H. 978 mb
L. OPEN NW
M. C12
MAX FL WIND 79 KT NE QUAD 15:24:00Z
MOAT 8NM WIDE CENTERED 16NM RADIUS AROUND EYE NW THRU EAST