what is new, is that now there are 'confirmed' sources indicating that this announcement is going to happen on Monday, at the 2005 World Wide Developers Conference of Apple's. (Why monday? thats when Apple CEO and iDeity Steve Jobs will be giving the keynote speech.) Mac OS Rumors, a rumor site that i've followed off and on for the last few years, indicates that it maybe more of a business server line switch or addition to the product line rather than the consumer / 'prosumer' models that we're used to seeing.
i tend to believe this rumor spin more so than others - why? its less of a "OSX WILL RUN ON A PC!!!" style of rabble and more believable because its an evolutionary path - OSX to Itanium™ style chipset.
all i know is that its been a long time since Apple announced anything really new. everything so far has been evolutionary changes to the base systems. and by new, i mean iPod like. maybe its time for the iTablet or a new pda like device ala Newton?