JG,

I don't believe the Gulf Stream will have any impact on the forward speed of the storm. At it's current intensity or intensities slightly higher, the steering flow is almost exactly the same (and forecast to be such through time).

The only thing that could really start to send it further to the north is a rapid intensification (due to increased Beta effect...think along the lines of increased influence due to Coriolis), but by then it will already be near land and likely to lose that punch once it hits land. SInce it is such a large storm, I do believe the envelope for intensification will close sooner than it did for Charley and Andrew, both of which strengthened to landfall.

It may slow a little bit more in the short-term, then begin to move with a little more urgency through time. Just don't expect anything like the 15-20mph movement the storm had before Frances came through. Hope this helps...