I have it today.

Droped 3 fps just sitting at my test airport under dx9 but other than that, didn't notice much of a difference either way.
DX10 however, with same settings, had a 90% drop from 20 down to 2 until I turned off aircraft shadows and antialiasing. The end result was that DX10 looks like poo, doesn't seem to give me anything over DX9, and is more or less a dissapointment.
I also notice that the raindrops still don't show on my windscreen allthough I am positive Phil taylor blogged somewhere that they where added, and my F-18 has a case of the boing boings when landing (starts pinballing round the sim like a superball), my runways flicker constantly wherever the runway texture overlaps the taxiways, and half my 3rd party plane slow the sim to 1 or 2 fps as well as losing their textures.
Top it all of with the fact the with the exception of the water, the sim looks pretty much the same in DX9 and DX10, This "preview" has me convinced that DX10 isn't all it was hyped up to be.  Might just be my machine, but its the second game I have tried that ended up with DX10 looking the same or worse than DX9, but running noticably slower.
Like I said, might just be my setup, but I am not at all impressed. 

Hmmm, given that I am the only one grumbling, that pretty much decides it has being an issue of problems on my machine rather than acceleration itself. 
     Nvidia just posted new Beta drivers, and I am grabbing those to see if it makes a difference. If not, I'm going to have to start removing addon planes and see if it's one of those.  I doubt it though. I started with a fresh install of FSX so I wouldn't mess it up with cfg tweaks and scenery texture replacements I had going, and the planes where just a handfull I installed last night for kicks.
     I purchased a game by the name of "World at War" recently, and it has the same slowdowns with no benifits visually under DX10.  Now I am starting to think it's something with the card itself (GeForce 8600 OC I believe, but I am not at home to verify. Deffinitly 8600 though, and deffinitly has DX10 suport) which isn't so bad, has it's only ment to hold me till I can divert the funds for whatever powerhouse GPU is king of the hill in six months or so.  Pitty though, I have been very happy with the sim run under DX9.

Hehe, I just spent $260 on my 1/18th scale millitary toy/toy plane addiction this month, an I bet that the old lady would probably throw a fit if I ran out and bought the 8800 right now, otherwise I'd probably be leaving for Best Buy in the next hour or so....
She's allready ticked enough that I have filled the house and two storage spaces with giant toy planes and tanks. She might just have grounds to murder me over my aviation addiction, but buying a new card is just so, so....
Nope, better behave. lol

Ussually I'd agree, but for some reason, the one by me is always selling stuff for lower than the other Best Buys. Quite often lower than the marked price on it's own shelves in fact.  Given the fact that it does, and I live in the middle of a low population area in Florida, it's often worth going there first and paying the extra money rather than spending the cash on gas for  driving to other places, and like I said, I quite often end up with surprise discounts to boot.

For one you can no longer log on to the old servers so for now there are only a couple of
not so interesting sessions. Number two is that most people cant seem to host sucessfully.
looks great in single player and missions are awesome but multiplayer sorry to say needs
a new service pack. excited but disipointed

Most of my older craft work fine, but I've got quite a few FSX generation freeware that don't have their textures, and in some cases have a majority of parts invisible all together.  I'm not sure how many of those are ports.
I managed to fix some of what I had listed wrong with my sim in above post, but I am still stuck with visual issues with planes. In addition to blank white planes and clear parts, My cockpit shadows show up on the outside of the plane sometimes, and I still have problems with runways, taxiways, and painted markings flickering where they overlap each other