It is not about generic PDFs (Score 1)

The only thing that could get Adobe nervous is if M$ is trying to incoperate some of PDFs higher functions. Indexing, built in scripting, 3d support, web push/pull, backend DB support. Imagine If you could have a PDF that links to a spreadsheet or DB even after it is created. This would esentially give you the same workflow possibilities of Office w/o having to spring for Acrobat Pro. Just printing pdfs is simple and free. The higher functions are a pay to play area.