We sholud ask Samsung for an official statement on their website. They should say only:
Yes, Froyo for Spica will be available officially, OR
No, Spica won't get 2.2 upgrade.
This is it, there would be no more questions about it.
Is there a reason, why not to ask them? Seriously. I'm hunting every piece of infos about Spica&Froyo, and they could solve our problem with a single sentence, on their website