If I remember correctly, the POSKY 737's for FSX were done as a test. Later models were developed for FS9, but had aircraft.cfg's that included FSX parameters (which FS9 simply ignores). A few days to a few weeks later, you can generally expect to see an FSX model replacement that will allow you to import one of the default VC's, but (again) generally speaking, the FS9 package should port over to FSX with relative ease. There is no FSX model update for the Poseidon, nor are there any plans for one that I'm aware of.