The Mac I’m using today — without question the best computer I’ve ever owned — is almost certainly my last Mac.

This machine is a Macbook Air, a 13-inch model that came out last year. It is a stunningly fine combination of size, style and power. And Mac OS X 10.6 “Snow Leopard” is a terrific operating system. I’ve customized it for my needs, and have truly enjoyed using it.

Because so much of my work depends on having a reliable and up-to-date computer, I buy a new one each year, using the older one as a backup in case of trouble with the newer machine. In recent years, that has meant owning two roughly equivalent Macs.

The latest Macbook Air went on sale this week. As is always the case with technology, it’s even more powerful than the one I have. I crave it. I won’t buy it.

Here’s the key issue: Not only does the new model come with OS X Lion installed, it will not run Snow Leopard at all. 

Lion is far too new for me to trust as my primary OS. And it is a radical departure — so radical in key ways that I can’t imagine _ever_ trusting it.

The hardware issue is entirely Apple’s choice. On these new Macbook Airs, using Parallels or VMWare Fusion, I could install any version of Windows or Linux on the new Air, and they’d run, provided there was support for the hardware. The only gotcha, for the moment, would be the Thunderbolt port. I assume Windows and popular Linux distributions, even older versions, will add support (if they haven’t already). But Apple’s policy is to make it impossible to run earlier Mac OS versions on its new machines, period. If there turns out to be a way to install Snow Lion in a partition, that might help, but I see no sign of that in the research I’ve done.

This wouldn’t be a big issue if I liked Lion more. Some of the changes look terrific, based on reviews. Others are more questionable, even though they’re designed to create a more modern structure — in itself a worthy objective but not when forced on users who have become accustomed to perfectly workable earlier methods.

Still other changes, however, are plainly designed to push Mac users into a more iPad/iPhone-like ecosystem, where Apple gives you permission to use the computers you buy in only the ways Apple considers appropriate. The writing has been on Apple’s wall for some time. It’s aiming for absolute authority over the ecosystem in which all its devices operate. Given the well-chronicled consequences of the company’s control-freakery in the iOS ecosystem, which is being merged with the Mac, that’s unacceptable — to me, at any rate, even if it’s just fine with everyone else.

For the past year, I’d been slowly working to move my desktop/laptop computing over to Linux in any case. It’s slow going for a lot of reasons, not least of which is my inability to replace several must-have tools, notably sparse disk image bundles and several superb applications I use for my blogging and other media creation.

In most ways, Ubuntu runs nicely on the new ThinkPad 220, a computer that is probably the best in its class. Yet I often feel about the experience the way I used to feel about the Windows-Mac comparison that’s held true for so many years: It tends to get in your way, while the Mac tends to get out of your way.

By rejecting its past so thoroughly — a proud history of creating devices that we users could modify for our own purposes with no one’s permission but our own — Apple is forcing me to move on.

An ugly mood in America today…

At a bed & breakfast table this morning, the conversation among the B&B customers turned to yesterday’s verdict in the C**** A****** trial. People were incredulous, bordering on angry, at the acquittal. They _knew_ this was wrongly decided, and never mind the damn jury.

One woman announced that her friend watched the trial on TV and was certain that the defendant was guilty of murder. Another said, “She went partying after hearing her child was missing.”

I asked, as mildly as I could, if being a bad person is grounds for a murder conviction, and who were we to tell the jurors, who were actually there in the courtroom for the trial and ultimately didn’t believe this case was proved beyond a reasonable doubt, to say their doubts were unreasonable.

I got a couple of hard looks from others at the table. Happily, the conversation turned to other topics.

Then, on Twitter, I saw reports that the ever-odious Nancy Grace had essentially told a national TV audience that the verdict was BS. I know, this is her stock in trade: inciting the public to hate defendants she dislikes. But it’s dangerous stuff.

Maybe C.A. did it. Instead of bemoaning a verdict of not guilty, though, we should be cheering a system where, at least on occasion, the presumption of innocence — and a requirement of proof beyond a reasonable doubt — still means something.