Citrix's application networking software is not as user-friendly as competing software sets, making it more likely that customers will go to F5 or Cisco for their app networking needs; in the high growth market, this as powerful negative implications for Citrix's revenues.
The Windows Vista effect, incarnated through the inclusion of certain centralization functions that are offered by Citrix with Windows Enterprise Server, could remove enterprise user incentive to shop to centralization software, thus cutting much of Citrix's revenues.