Hi Scooby,
I don't have much information about weight. They said they went through the boat with an eye towards reducing some of the weight in the layup, however, they decided to keep the structure in the front of the hulls the same because so many want to have the bridle instead of the dual forestay. It makes the spinnaker easier to gybe but requires more structure to prevent hull deflection when mainsheet loads are high. The new daggerboards have not been incorporated into the new boats that arrived in Michigan this week, however, the new boards will be exchanged for those who bought these boats when they become available. This is true for the revised/redesigned boom, also.
I've been told that the prototype "Big Boy" spinnaker design is what will go into production, and it is smaller than your 19 sq. m kite. It uses the entire available space from pole end to mast fitting, uses the same aspect ration as the current F17 standard spinnaker (between 15 and 16 Sq. m). Some say the Big Boy is fuller, also. I have been told the S. A. is between 17 and 18 sq. m.
The shape of the blades will differ from the current blades in being 8" shorter but the lower part of the leading edge will share the shape of the new F18 board (conceptually). I don't think design has been finalized. Boom system will be lightened (4 lbs.?) and incorporate the rotator system Europe is already using. They are supposed to fix the outhaul, also.
You will love the carbon mast and bigger mainsail. I first sailed my 2000 I17 with the stock aluminum mast and smaller mainsail and there was a significant improvement when the carbon mast/mainsail was installed. I have nothing against choosing the FX-1, but those I talked to that have sailed the I-17R and the FX-1 here in the US (2 people) said they prefer the NACRA, "no contest" (their words, not mine). Make sure you know what you are getting into before you switch.
All that being said, you can see that I just had to get an A-Class!