Yeah, there are a lot of things being "promised" to be in Longhorn, and possibly a lot of things that WILL be in Longhorn that we don't know about today. 2-3 years is a long time, it's a little pointless to speculate.
It is, however, a good idea for MS to be more vigilant.
My thoughts on the matter - if MS releases an OS as good as, say, Jaguar or Panther, then Apple will have their work cut out for them.
Today the OS gap is REALLY wide, which gives Apple a clear distinction and advantage over the MS platform. It's really what got me into the platform, I know, and really what anyone I know that has expressed interest in Macs has been interested in.
It's not just the features of the new OS - it's the fact that components of Windows just bug people on a day to day basis.
Now, if Microsoft is able to put out an OS that's about equal to Jaguar, let's say, and we have two (or maybe 3) more Jag->Panther equivalent improvement releases in the meantime, then I'd say that Microsoft will have closed the gap quite a bit - which makes the Mac platform that much less interesting as an alternative.
In my mind, all MS has to do is make Windows 80% as good as MacOS, and they'll see a lot of people switching back, because that 20% difference doesn't make up for the other disadvantages (or perceived disadvantages) of the Mac platform (and because of all the anti-competitive stuff that MS keeps getting away with).
I like to be optimistic, but it's probably also worth keeping in mind that Longhorn could essentially kill the Mac. It's mostly pointless to speculate at this point - in three years Apple might invent and patent a system that makes notebooks run for months between charges, and a meteor could level Redmond, WA. Speculating about these is probably just slightly less valuable as speculating about what will happen with Longhorn. And probably more fun =)
