At Microsoft's introduction last week of new versions of Windows Server, SQL Server, and Visual Studio, CEO Steve Ballmer had reason to smile, at least on the Windows front. Our survey of 1,082 business tech pros finds that 56% expect to adopt the new version within two years. Gartner reports that Windows, with almost 67% of the server operating system market, gained a point of share last year, while Linux slipped a point to 23%.

Windows Server 2008 should be more secure thanks to features such as Network Access Protection and a more modular installation option, more manageable with its Server Manager administrative dashboard, and more useful, once final virtualization software is included. But there are risks with Windows Server 2008. We talked with Ballmer, and customers, about those.

• Late to virtualization: Don't count on a final version of Microsoft's Hyper-V before summer. Meantime, rival VMware keeps digging in (see VMware Moves To Counter Virtual Machine Security Threat ). "We're very active in virtualization, but we're a VMware shop, so we really have not looked at the Microsoft offerings yet," says Lou Sneddon, a director at telecom company Global Crossing.

Microsoft says just 5% of servers are virtualized, so it can still take it to the masses. Says Ballmer: "Virtualization is way too complicated, way too expensive today for people to take advantage of it, and it's way too isolated from the rest of everything that happens in application development to data center deployment and operations." Microsoft says it will integrate virtual machine management with its management tools.

• Windows' bad security rep: John Wilder, director of IT at Youville Hospital in Cambridge, Mass., doesn't buy that Microsoft's more modular installation option, Server Core, will mean better security and less maintenance because there's less code on each machine. "If it's a patch that deals with security, you know it's going to have to be installed on every server," he says. Adam Baum, IT architect for the city of Mesa, Ariz., isn't impressed with Microsoft's Network Access Protection and will stick with the multiple-vendor security he has. But San Diego Zoo CTO Robert Edhardt likes the fact that "you don't have to buy 15,000 [security] products anymore to do what's now in the operating system."

• Application compatibility: This issue worries 73% of the tech pros we surveyed. "We have a lot of niche products, and those guys aren't quickest to upgrade," says Baum. Ballmer says 500 apps will be compatible with Windows Server 2008 in coming weeks.

• The "wait for Service Pack 1" mentality: "We're not going to be an early adopter. We never are with Microsoft," says Wilder. Microsoft's trying to break this mind-set, with Ballmer calling these versions of Windows Server, SQL Server, and Visual Studio "the most-tested releases we have ever done." More than 2 million Windows Server test copies were downloaded, and it shares some code with Vista, so some bugs already have been found and fixed.

• Open source--and openness: Though Windows has gained ground by some measures, 23% of our survey respondents are looking to increase their ratio of Linux servers to Windows. Last week, the European Union fined Microsoft $1.3 billion for not complying with orders to license communications protocols at reasonable cost. But Microsoft's budging here, saying recently it would provide protocol documentation free on the Web. "If innovative work is going to happen in the open source community, I want it to happen on our platforms," Ballmer says. There are even signs of this move within Windows Server: Its Web server, IIS 7.0, includes support for PHP apps.