Clearly you've got passion about the topic. Maybe you work for Covast, don't know. And it's only my thoughts here, not my employer.
I bought my wife a RAZR phone a year+ ago and spent $400. Now I could buy one for $79. Phone is still good, I just spent more money up front to fill a need. Someone who bought BizTalk 2006 + Covast 2 months ago, will still have a perfectly good working solution 1,2,3 years from now. Could they get the base capability for "free" in 12 months? Yes, but most of my customers have needs today, and need solutions today. I haven't stopped telling folks about Covast, but I also let them know where the BizTalk product is heading. While we'll have upgrade assistance ready to move from Covast to the R2 stack, there's no reason the combination purchased today would be less than useful.
I haven't been involved in the politics of us adding this offering, but I suspect that we believe this is a long-term win for customers. Same things as with the adapters last year. I had customers buy the Peoplesoft adapters from iWay, and shortly thereafter, we purchased the IP and "gave" it away for free. In my experience, my customers were less depressed about the $$ already spent, and more excited to actually get quality support from Microsoft for the bits and be assured of a long term integrated platform. But, I'm sure others feel differently. Can only go off my own experience. Admittedly, this is a tricky time window for someone like myself in technical sales/consulting because I need to position solutions that work right now, while also educating my customers of long term implications of an investment today.