Microsoft was early campus-wide WLAN deployer, but needs new technology: The company has made extensive use of its WLAN infrastructure, but is facing the same growth pains as everyone else. There's no capability for VLANs, so all users get the same network privileges, making it impossible to offer guest access without them having set up a separate guest WLAN. Microsoft was an early 802.1X user, too, deploying an internal public-key infrastructure based method (EAP-TLS) which required the irritating installation of individual certificates on every computer that connected to the WLAN.
What was good for Microsoft was good for the industry, too, resulting in the good and ever-better implementation of Wi-Fi support within Windows XP. It still baffles me, however, that there's no location and profile manager as Apple has had for what I think is going on a decade. Even with Windows XP, you have to set up preferred networks that can be accessed universally as opposed to specific networks for specific location profiles.
Microsoft is taking bids, and I wouldn't be surprised if a WLAN switch vendor wins based on the requirements that they have for VLANs across WLANs and the entire campus, alongside their new interest in VoIP.