On June 30, 2008, the last PCs with Windows XP were sold (theoretically) and Microsoft (NASDAQ: MSFT) went hard on Vista, its less than celebrated operating system. I was one of the hold outs, opting to buy my laptop with Windows XP last year even though Vista was being touted as the latest and greatest system. Today, I am sure the remaining XP devices are going for a premium.

What does this mean for the future of PC sales? I think there will be some measure of reduced PC sales in the short run just because the economy is already suffering and consumers and businesses are looking to stretch their devalued dollars.

It also means that some people that do not want the burdensome Vista system and all the baggage that goes along with it will be opting for Apple (NASDAQ: AAPL) Macs. There are many people like me who have been weighing the switch to a Mac for a while. The rest of my household has made the switch (4 Macs, 1 PC) and I did consider this prior to my last purchase. I may swing the other way next time.

For other PC users who remain satisfied with XP, they may not only think to stretch their dollars, but try and hang onto their PCs longer until the value proposition for Vista becomes more convincing. I can always add more memory or speed to my existing computer.

I do not know what the trade-off is for Microsoft. It would make money selling the XP system as well as the Vista system. Any slowdown of PC sales or continued movement toward Apple products has to hurt revenue a little?

Sheldon Liber is the CEO of a small private investment company and the principal for design and research at an architecture & planning firm. He writes the columns Chasing Value and Serious Money.

As Microsoft shareholders let out a gigantic sigh that erased $2.8 billion in market cap, the company's stock flirted with its 52-week low of $24.00 during the afternoon. It finally closed just barely above that solid line, at $24.01.

Contributing to the terrible performance and two-and-a-half-times-average volume: the prediction by Gartner that Microsoft's latest and greatest (?) operating system, Vista, might be delayed another three months. According to one Microsoft employee, it's so not true, and Microsoft insists that it will still make the November 2006 (volume license customers) and January 2007 (everybody else) launch dates. Shareholders? Clearly are not drinking the Kool-aid.

Say it with me [long deep breath] ***SIGH***.