With those words, spoken at a big company event in New York City (see video below), the Microsoft CEO launched the newest version of Windows, the one he hopes will regain the customer goodwill lost with its predecessor, Vista. There’s no question that the stakes are particularly high this time around. Vista was widely maligned as mediocre, and Microsoft (MSFT) needs something to reverse three quarters of declining Windows sales.

By most accounts, Windows 7 fits that bill. Reviews of the new operating system have been largely positive, calling it faster, more secure and easier to use that its predecessors. Our own Walt Mossberg describes it as “the best version of Windows Microsoft has produced…a boost to productivity and a pleasure to use.” Quite an endorsement, but one that was hard won. According to Microsoft, more than eight million people participated in the Windows 7 beta program–more than for any Microsoft beta program ever.

In any event, if any OS has a shot at succeeding Windows XP as the world’s most ubiquitous operating system, it’s Windows 7. “I think Windows 7 will be the biggest, one of the biggest, products to hit the tech industry this year,” Ballmer told CNBC. “Just because Windows is used on about one billion computers around the planet. There’ll be another 300 million machines that ship this year, and the diversity of PCs that ship with Windows 7, the simplicity that Windows 7 brings–I think it’s a pretty banner year.”

If ever Steve or the board of directors decided that he was no longer capable of doing his job as CEO of Apple, I’m sure they will let you know.”

– An Apple spokesperson

Three days of gains gone in just two minutes. That’s what happened to Apple shares today after Gizmodo published a rumor suggesting Steve Jobs’s declining health is the real reason he won’t deliver the keynote at Macworld 2009. Apple (AAPL) hasn’t yet commented on the report, nor has anyone who could reasonably verify it. And they almost certainly won’t; Apple’s longstanding company line has always been “Steve’s health is a private matter.” And those close enough to Jobs to comment on such rumors with any degree of authority surely won’t for fear that Jobs would brain them with the nearest Mac Pro.

But CNBC’s Jim Goldman–who earlier this month reported that Jobs’s decision to skip the Macworld keynote had nothing to do with his health–is calling BS on the Gizmodo report. “I spoke to Apple after these headlines crossed and the company, which officially doesn’t comment on rumors, reiterated the reasons it offered two weeks ago: Apple was pulling out of Macworld because the company didn’t see the need to continue its investment in the expo, which included Steve Jobs’s keynote. I was told this morning (Tuesday) that nothing has changed since then. The same reasons apply today that applied two weeks ago. I was told two weeks ago by sources inside Apple that the decision had nothing to do with Jobs’s health. I got the same message today. Period.”

Which makes you wonder about the motives of these “previously reliable sources.” There’s sometimes a very fine line between solid sources and stock manipulators looking to make a quick profit. With little in the way of news this week, the Macworld keynote issue still fresh in our minds and Jobs’s health an obvious shareholder concern, a rumor like this one seems a little too perfectly timed, doesn’t it?

A quick thought on that last point: CNBC’s Jim Goldman says he’s sure Jobs’s decision to skip the Macworld keynote has nothing to do with his health. If that’s the case, tapping Phil Schiller to deliver the company’s final Macworld “Stevenote” likely has more to do with Apple’s acrimonious relationship with Macworld organizer IDG than anything else. Given the media attention the company’s able to command these days, Apple no longer really needs events like Macworld. The company’s special events are equally as effective in generating publicity and far easier to orchestrate and control.

So would Apple really send Senior VP Phil Schiller out onto the Macworld stage without a cool new product to introduce? Probably. So much for that netbook …

Shares of Yahoo spiked this afternoon on rumors that Yahoo is back in merger or partial acquisition talks with Microsoft. YHOO rose 5.2% to $22.56 in afternoon trading before falling to its knees again after a source close to Microsoft told CNBC there are no new negotiations between the two companies. “There is no deal for the whole company, and nothing has changed as of today,” the source said.

But as BoomTown notes, perhaps it should.

So why is it taking the company so damn long to respond to Yahoo’s latest stonewalling of its advances? Three days have passed since the expiration of Microsoft’s deadline for Yahoo to accept its buyout offer or face a possible tender offer and proxy battle. And we’ve heard not word one from Microsoft (MSFT), which had–up until Saturday–lobbed threats at Yahoo (YHOO) nearly as often as it issues security bulletins for Windows.

Well, that may soon change. People close to Microsoft tell CNBC that the software giant is girding itself for a proxy fight. And CNBC, noting a sudden upward trend in Yahoo’s share price today, speculates that Microsoft may launch its opposition slate of directors as soon as tomorrow.

Or it may not. A source with knowledge of the situation tell BoomTown that Microsoft may make good on its threat to scrap the deal. “I would not have said this yesterday,” the source said. “But I would not be surprised if they walked away rather than waged war.”