Just wanted to state that XP will still be good for Offline or Private LAN use where there is isolation from the internet but it can still serve a purpose.
I own 6 copies of XP ( 2 x Home and 4 x Professional ) and have no plans to throw the towel in on them for use Offline or Private LAN communications where these are still usefull.
In past years I continued to run prior versions of Windows Desktop and Server OS beyond the supported life placed on them by Microsoft. Windows 2000 Pro SP4 I used for many years beyond security support for Offline or Private Lan use mainly with Pentium 166Mhz & 200Mhz MMX and Pentium II based CPU systems that were not ready to be thrown into a landfill, and it didnt make much sense to install XP to with just 192MB RAM etc, yet Windows 2000 Pro SP4 with 128MB RAM or more worked well for the needed purpose at the time vs spending money.
However Linux made vast improvements in hardware and software support and so I was able to do away with some that I was using as file servers etc and replace the older Windows OS without further security updates with Linux which was free and had security updates available.
Since there are still some applications where XP will be needed vs Linux Offline or Private LAN, I will continue to use my licensed copies of them for years to come as I did in the past with the other OS's that phased out.
I think one thing that people should consider is to try out a Linux Desktop OS which is free such as MINT, Fedora, or Ubuntu, etc if they have an older system that isnt worth putting money into and they dont want to spend money but still want to be secure from security problems.
One example of a system I have that is older and works well with Linux is a 2002 model eMachine that is running a Pentium 4 2.0Ghz with 1GB of RAM. I am running Linux MINT 16 ( 32-bit ) on this system and it runs well and it is secure. I use this system for surfing the web on one display while I am doing something else on the other through a KVM to share keyboard/mouse, but each system has its video connection direct to monitor. *Some may say why dont you just use a single system with dual video displays, but the reason for this is because some older games I have have issues with dual display mode systems, and also I like being able to switch between Linux MINT 16 32-bit and Windows 7 64-bit on the fly with the KVM.
So anyone who isnt ready to send their older computer to the landfill should consider burning a DVD of Linux and installing it to an older machine if they want to stretch the secure life of the computer further without spending money. *The only users this wouldnt work out for is gamers since Linux can be tricky getting games to run and some will not run on it. But if you are a gamer then you will want up to date hardware anyways. And if you like playing older games, chances are they can be played offline and so this XP system can be retained as a system to play the older games etc and with a KVM you can switch between this older Offline system running XP and your newer system with Windows 7 or 8 / 8.1.
Lastly it is beneficial to retain that older system if you have older 16-bit software or programs that you dont want to stop using because 64-bit versions of Windows have no 16-bit support. The 32-bit versions of Windows support the 16-bit software or programs, but you would not want to buy into a modern 32-bit OS and then be locked down to a maximum of 4GB of system RAM to use for the OS. So because I have lots of older games that some work ok with DOS Box etc and others dont, its best to play them on the older hardware offline when there is that need to play a 16-bit version of Tetris etc without buying a newer version. Although this is probably a weak example since there is probably a free to play web based version of Tetris out there with a different name to avoid legal issues.