Is it a little strange? Support dates for XP and Win7.

XP mode is unsupported when XP EOLs - it was meant as a solution to provide an application compatibility bridge for users migrating to Windows 7 starting 4 years ago, not to extend the life of XP. It's not strange at all, and yes, it probably brings vulnerabilities with it if you continue to use it 5+ years on.

Granted, xp mode runs in a virtual machine so its a tad more protected then to just running natively. (As in affecting windows 7.)

My suggestion would be to use a more secure solution and to integrate xp mode into VMware player. VMware player does not share the os files and stuff by default. The main point in xp mode is to share files and emulate programs in the windows 7 environment.
VMware player blocks this by default so its a tad more secure. Another thing is you could disable the xp vm from the internet, or only keep it on the intranet if its a company.

Just some thoughts. There are many ways to "harden" xp that could be done as well.
You can really lock down xp using group policy as well as other methods found online. That alone would help the machine be less likely to attack and malware. The issue though, is any new vulnerabilities found will not be addressed.

So to recap:

In terms of security:


Malware could potentially go through the xp mode virtual machine and attack the windows 7 OS. Just because xp is in a virtual machine does not make it completely safe. But it does make it a lot safer then just running xp natively on a machine. Having an antivirus and something like malwarebytes on both Operating systems is a good place to start.

Most effective:

-Get rid of xp all together:
-XP in limited account in VMware with no internet or connection of any kind.
-Locked down with group policy

Moderately effective:

-Xp in limited account in VMware with intranet connection only.
-Locked down with group policy

Least:

-Xp mode with limited account and a connection to internet or intranet.
-Locked down with group policy.

My opinion.