This comes hard on the heels of the VMWare IPO. An eWeek article suggests, "The Citrix-XenSource deal might pressure VMware to drop the price on some of its products. To increase the pressure, Citrix announced that it will begin selling XenSource's products through its roughly 5,000 channel partners."
How will this affect the open-source Xen hypervisor? The press release says, "The acquisition will also strengthen each company's strong partnership with Microsoft and commitment to the Windows platform." Does that mean a change in direction?