When CEO Steve Ballmer gave a quick peek at an HP Slate running Windows 7 at CES in January, Microsoft seemed prepared for battle against the iPad, which, at the time, had not even been announced yet.But since then, Microsoft's Windows 7 tablet strategy has largely been to spin its wheels as iPad sales surge and Android-based tablets gain increasing momentum, industry analysts say. Last month at Microsoft's Worldwide Partner Conference, Ballmer said that there will be Windows 7 slates out in time for the holidays, but no firm release dates have been announced yet.If there are any Windows 7 slates ready to launch this fall, writes veteran Microsoft watcher and ZDNet blogger Mary Jo Foley, expect them to be "business-focused devices that do not have the long battery life, touch-centric user interfaces or built-in app store capabilities" of consumer slates. In other words, not an iPad competitor.Meanwhile, the iPad train rolls on. In late June, Apple announced that in the three months the iPad has been available in stores, it has sold three million units. The iPad is also starting to make inroads at enterprises, according to a recent Wall Street Journal article.The MSI WindPad running Windows 7 has been pushed from a holiday 2010 release to a 2011 release. It sports a 10-inch screen, Intel's latest power-saving CPU platform, 8 hours of battery power and multi-touch control. MSI is also developing an Android WindPad slate that is set to ship before the end of the year.Also taking the wind out of Microsoft's sails: Hewlett-Packard's $1.2 billion acquisition of Palm in April. Last week, HP announced it will be using Palm's WebOS in a consumer tablet PC set for early next year. But HP is still set to use Windows 7 for its business-oriented line of tablets, though it has not specified timing.Microsoft must also contend with the many non-iPad tablets running Google's Android mobile OS, which continues to win over more consumers through the popular Droid smartphones. One of the most anticipated Android devices is Samsung's Galaxy Tab, which is smaller than the iPad with a 7-inch screen, but has standout features such as front and rear-facing cameras, video chat and support for Adobe Flash. It's expected to ship this fall.Other Android-based tablets available now or on the horizon include Cisco's Cius Tablet for businesses, Dell's 5-inch Streak, Toshiba's 10-inch SmartPad and ViewSonic's 10-inch ViewPad device, which can boot either Windows or Android.Still, it's a long shot that any tablet PCs, Windows or Android, can compete with iPad momentum, says Tim Bajarin, principal strategist at tech consulting firm Creative Strategies, who believes that Microsoft should not even bother to rush Windows 7 tablets for the holidays."Tablets are still in their infancy and Apple has sewed up this space through the end of this year," says Bajarin.For its part, Microsoft has been beating the drum about upcoming Windows 7 slates from big-name vendors like Dell, Samsung and Sony. [ For complete coverage on Microsoft's new Windows 7 operating system -- including hands-on reviews, video tutorials and advice on enterprise rollouts -- see CIO.com's Windows 7 Bible. ]"Over the next several months you will see Windows 7-based slates that I think you'll find quite impressive," said Ballmer at WPC in July. "This is a terribly important area for us. We are hardcore about this."Microsoft does have a few Windows 7 tablet PCs available now at different prices and form factors, such as the Archos 9 Tablet, Asus T91mt Eee PC and Toshiba Portege M780-S7220. An MSI WindPad tablet running Windows 7 was planned for the 2010 holidays but was pushed into early 2011. MSI is also developing an Android WindPad slate that is set to ship before the end of the year.Although Microsoft may be "hardcore" about tablet PCs, it has to worry about more than just meeting a holiday or early 2011 deadline, says veteran tech analyst Roger Kay. Kay believes that Microsoft had years to innovate with tablets, but failed to do so quickly enough and did not design Windows 7 with tablets in mind.[ For complete coverage on Microsoft's SharePoint collaboration software -- including enterprise and cloud adoption trends and reviews of SharePoint 2010 -- see CIO.com's SharePoint Bible. ]"Windows 7 is too heavyweight to meet the battery and responsiveness requirements of tablets," says Kay. "At this point, Microsoft has conceded the field to Apple and the Google camp, and its best play is to sit this holiday out and prepare something for next year."It may be true that the 2010 holiday season belongs to the iPad for tablets and that laptop-minded customers are not ready yet for tablet PCs. But 2011 will be the year when the tablet wars begin in earnest, says Bajarin, and Microsoft can't afford to be late."If Microsoft wants to be as serious player in this area it needs to be out with Windows-driven tablets by the second quarter," he says. "By the 2011 holiday season tablets will be one of the hottest segments of the mobile computing market."Shane O'Neill covers Microsoft, Windows, Operating Systems, Productivity Apps and Online Services for CIO.com. Follow Shane on Twitter @smoneill. Follow everything from CIO.com on Twitter @CIOonline. Email Shane at firstname.lastname@example.org.