Posting this query here rather than to individual forums to get widest audience.

Is it 100% certain that when Delta and North West seal the deal, miles from both programs will be merged into one with no loss/devaluation?

Gart Steiger says on his site Flying Blue are merging their FF program with Skymiles. Is this more than just rumour. I have miles in all three programs and will take no action if the above transpires.

Thanks in advance to those more knowledgeable than me.