Althought the original galaxy S DID get a sense build, it wasn't quite perfect and had it's fair share of issues. This is because the hardware used on HTC phones is based on Qualcom chipsets, while Samsung tend to use their own stuff.
For a port to work, one must extensively hex-edit a Sense rom for it to boot, then modify core apps and firmware issues.
As it stands, it is Highly unlikely to see a Sense 3.0 rom on the S2. That being said, if HTC does in fact come through with their promise to release the Sense Kernel SDK, then the chance of a port rise exponentially.
At that point you would require dedicated developers who would need to spend countless hours creating such a port.
I hope that answers your question, but to be honest, no one knows what the future will hold and short of having someone currently working on a port, no one can know if it will happen.
