Windows XP End of Life - What Security Risks have you just inherited

When thinking about XP, I look at a operating system that is now vulnerable and open to attack through various vulnerabilities that may be found in the future. Its a hardened and true operating system that has been secured by years of security updates and patching. For those organizations that are going to continue to use the OS, you have to start investing in a defense in depth layers security approach that can detect vulnerabilities that XP may be discovered in the near future. You will want to implement the following types of technology to mitigate the XP risk:

Host:
Implement Desktop Encryption
Anti Virus the produces logs that are monitored 24/7
Malware specific Software
File Integrity management (FIM) solution
Implement digital signatures and encryption to you meal client
Web Browser Protection

Server:
Centralized Log Management Solution monitored 24/7
Centralized Patch Management Solution
Password Rotation 30-60 days
Antivirus on all servers that produces logs monitored 24/7
Implement a web and mail filtration solution that produces logs that are monitored 24/7
Utilize a security scanner regularly test for vulnerabilities
Leverage the cloud for data that can be shared

Network
Centralized patch management solution 
Log all devices to centralized logging solution that is monitored 24/7  and is consistently updated with correlation logic
Collect and analyze netflow for anomaly detection. Make sure to update blacklists regularly
Utilize a security scanner regularly test for vulnerabilities
Firewall with tight access controls dropping unneeded countries of business
Implement IDS/IPS solutions that are monitored 24/7  and are consistently updated with content

Security
Implement deep packet forensics collection that supports the 24/7 analysis
Implement Forensics solutions for investigations
Implement Security Incident Event Monitoring (SIEM) technology that is monitored 24/7 and is consistently updated with content
Build Security Operations Center that is staffed appropriately for 24/7 monitoring, incident response and risk mitigation

The technologies mention above are sample of what needs to be implemented as part of a security in depth solution. The problem that usually occurs when implementing these technologies is that the personnel are not staffed appropriately or educated sufficiently to support the technologies that are being deployed. This is where people begin to look at managed security service providers for those expertise and personnel to monitor the implemented technologies 24/7. Thus you need to properly and intelligently invest in your security program and partners to mitigate the risks that Windows XP might produce in the future by no longer being unsupported.