So now it comes down to the desktop. Microsoft, in its ongoing slugfest with SAP, has a new fighter in its corner: Dynamics user interface software based on the latest versions of Vista and Office 2007. The only problem is whether that capability represents a genuine advantage or a potential liability.

And it's your job to figure it out.

At issue is the disparity between the number of desktops that run enterprise software systems such as MySAP and Dynamics AX, NAV, and GP, and the desktops that don't. According to AMR Research, only 15% of desktops in any given company are running ERP software, which means 85% aren't. That difference gets under the skin of vendors like SAP and Microsoft, and not just out of concern for customer productivity. A number like 85% represents a huge up-sell opportunity, even at the reduced rates most vendors give more casual users.

Hence, SAP's successful Duet product, which places SAP functionality into a classic Microsoft Outlook interface. Imitation being the highest form of flattery, Microsoft is now pushing its Duet-killer, a set of prepackaged processes and a tool kit that lets customers and partners build Office-based applications that leverage all those back-office processes in Dynamics.

Microsoft is counting on the tool kit as a strategic differentiator against SAP, which, as of Microsoft's March announcement, had no developer's tool kit. And the Dynamics gang is also counting on the advanced functionality in Office 2007, Vista, and the new business intelligence capabilities in SQL Server to further make a case for its desktop strategy.

And this is where the question of liability or advantage comes in. To fully benefit from Dynamics' new capabilities, many customers will need to install Vista, Office 2007, and a SharePoint server, plus, in many cases, buy a new PC big enough to handle the software. That would mean an additional price burden: $500 for a new computer, and $400 to $600 or so in new software — on top of whatever Microsoft charges for its Duet-killer.

There's also a compatibility problem with Office 2007. Its compatibility with previous versions of Office is hardly a slam-dunk. The file formats are incompatible, which means customers either do a work-around ("save-as" the older format or install compatibility plug-ins) or have to upgrade everyone -- and pray that their customers and partners have upgraded.

None of this is a problem if you plan to run Duet, which happily works within the Office "classic" and Window XP environments that dominate the desktop world. That means fewer gee-whiz graphics and other cool stuff that comes with Vista and Office 2007, as well as some genuine value-add. But it also means the barrier to entry for fully functional Duet could be lower than what Microsoft is proposing for many Dynamics customers.

Microsoft claims that the Office 2007 problem shouldn't be a big issue, though my casual survey at the company's Convergence conference showed some reluctance among customers to upgrade as quickly as Microsoft would like.

This desktop duel is great for you. It means more useful functionality is coming to your desktop. And with two big companies fighting for your IT dollars, this competition is sure to benefit all. That might not make the choice exactly easy, but it should reassure you that whether you go with Duet or the Duet-killer, your users will thank you.