Bloomberg reports unknown sources stating that only three Windows on ARM (WOA) tablets will be available at launch:

There will be fewer ARM-based devices in the rollout because Microsoft has tightly controlled the number and set rigorous quality-control standards, said one of the people. The new version of Windows will be the first to use ARM processors, which are most commonly found in smartphones. Windows 7, the current version, only works with Intel’s technology. Three of the Windows 8 ARM devices will be tablets, the people said.

This may be nonsense but I can see this playing out badly for Microsoft. I am making several assumptions here:

1. The design of Windows 8 is all about tablets. If it fails on tablets, then it has failed.

2. Windows 8 Intel tablets will not compete with the Apple iPad and will probably not do well. The main reason is the old one: Windows desktop is mostly unusable with touch alone. I mean, you can get it to work but it is not much fun, and that will not change.  Supplementary reasons are that Intel CPUs are less efficient than ARM which means shorter battery life, and that traditional Windows applications expect lots of disk space and RAM, and that OEMs will want to pre-install anti-malware and other foistware, and repeat the mistakes of the past that are driving users with relief towards iPads.

I can also imagine Windows 8 Intel tablets being sold with add-on styluses and keyboards that are necessary to operate desktop applications, but a nuisance in all sorts of ways.

3. Windows on ARM has more potential to be a compelling iPad alternative. Metro-style apps are designed for tablets and will work well with touch alone. ARM devices may be lightweight and with long battery life. The locked-down Windows Store is some protection against excessive OEM interference. With Microsoft Office compatibility thrown in, these might appeal to a business user who would otherwise buy an iPad.

Despite the above, my guess is that Microsoft’s OEM partners will instinctively put most of their effort into Windows 8 on Intel tablets, because that it the way it has always been, and because of an assumption that someone buying a Windows 8 device will want to run Windows applications, and not just Metro-style apps.

The problem is that such people will try Windows 8 on Intel tablets, hate them because of the reasons in (2) above, and end up buying iPads anyway.

The counter argument? That Apple conquered the tablet market with just one model, so perhaps three is more than enough.