While I was never a Macophile, I always appreciated the fact they were, by default, Intel- and Microsoft-free.
Intel and Microsoft are some of the most under-regulated monopolies since Standard Oil. Inasmuch as Apple still has any relevance, this new announcement only enhances Microsoft's monopolistic control of the industry, at the (slight) expense of Intel and of course at great expense to users.
Many people have suggested that Microsoft's motivation for this move is to keep a "competitor" alive and therefore keep the DOJ off its back. As minimal as Apple's competitive threat is to Microsoft, this move actually reduces Apple's threat, while at the same time maintains the appearance that Apple still exists as a competitor. A few aspects of the announcement show Microsoft's true intentions.
One is that they will bundle Internet Explorer with new Macs. Microsoft is working hard to make IE4 the desktop of Memphis and NT 5. So what does bundling IE mean for Macs? It really means you'll have a Windows desktop on your Mac. Sure, the low-level OS will still be MacOS, or Rhapsody, or whatever, but the low-level OS is of shrinking importance.
Another is the Apple/Microsoft collaboration on Java. What that smells of is support of "Java" windows apps, i.e. "Java" programs that use Microsoft classes that are only supported on Windows platforms. I put '"Java"' in quotes because these apps would not run on other Java platforms; they violate the "write once, run anywhere" principle. (Note: I'm a bit biased here; I used to work for Sun.)
These are moves toward making the Mac just another Windows platform. Microsoft has made many moves toward pushing Intel out of the Wintel oligarchy: they keep trying to get critical mass for NT on anything but Intel at the high end; they have been pushing the non-Intel WinCE (pronounced "wince") over Intel-only Win95 for the low-end. So far, Microsoft has been remarkably unsuccessful at this; we'll see how this new arrangement furthers their cause.
If Microsoft is successful, there will be less incentive for people to write Mac apps; certain kinds of Windows apps will run on Macs as well as current Windows platforms. Why get 10% of the market when you can get almost all of it? In turn, this lack of new applications will further decimate Apple's dwindling market.
What kinds of machines will be in peoples' homes? Old-fashioned Wintel machines, these new Macwintoshes, WebTV (owned by Microsoft). You won't be able to escape Microsoft's desktop except with a Unix variant, NC, other Java platform, or something even more esoteric. This could remove some of the remaining economic incentive for developers to write Pure Java apps, at least for the home market.
Hello? DOJ? Hello? It's exactly this kind of situation that antitrust laws were written to prevent.