The only way that would happen is if Adobe went crying to the FTC... which they would, which is why Apple offers first-class PDF support in the OS and Microsoft

The only way that would happen is if Adobe went crying to the FTC... which they would, which is why Apple offers first-class PDF support in the OS and Microsoft doesn't. An Adobe acquisition would render this a moot point. Full .PDF support would show up in Windows very quickly, which wouldn't be a bad thing IMO.