Apple likes to hold its product announcements close until they can release them with a flourish (and within the RDF) at one of thier myriad conventions.

MS tends to announce new stuff years advance while it is still near-vapor in order to gauge reaction and stifle the competition in that area (we should wait on that purchase because MS will have something to offer RSN). I have seen Windows rumor sites, but they are usually more along the lines of alpha/beta worship sites.

Linux? Kinda hard to have rumors about an OS that is developed in the open.

Amiga? What's that? ;)