Ballmer: Windows partners knew Surface was coming

Microsoft warned PC manufacturers that it was planning its own range of Surface tablets, CEO Steve Ballmer has confirmed, giving them advance notice it would be challenging them on their own turf. "Our PC partners knew in advance we were announcing something today in this space" Ballmer told AllThingsD in the aftermath of the Surface reveal, a pair of Windows-based slates targeting the iPad and enterprise markets, though the chief exec declined to comment on the reaction those OEMs had.

That reaction, though, isn't expected to have been especially positive. Microsoft has taken the Surface back to tablet basics, somewhat at odds with the hybrids and other form-factors OEMs experimented with at Computex. Having the developer of the underlying OS also challenge you with hardware products jostling for consumer attention is arguably not what Acer, Samsung and others were hoping for when they signed on for Windows RT.

Still, Ballmer is keen to stress that Surface isn't the sole basis of the Windows tablet strategy. "It's an important companion to the whole Windows 8 story," the CEO said said. "It's an important piece. It's not the only piece." Whether he was referring to other OEMs being involved, or more Surface-brand hardware from Microsoft itself, is unclear.

In fact, Ballmer suggests that Surface is really more of a spark in the style of Google's Nexus program than it is a direct rival. The new tablet line-up "gives people a full range of things to think about, sort of primes the pump for more innovation around Windows 8, [and] brings new technology to the Windows PC platform."

There's more on Surface in our full Microsoft event wrap-up and in our hands-on with the tablet itself.