Nope. But the only difference is the boot sector. I would
1) Wipe the target drive. Decide how you want to allocate the space on it: X GB for your Windows 7 clone, allowing for future growth, Y GB for the XP clone, and possibly Z GB for a third partition for data only.
2) Clone the Windows 7 drive to the target drive. If the clone process allows you to size the target partition, adjust it now. If not, do this after the fact with the drive manager. We can provide help.
3) Make partitions Y and potentially Z, using the drive manager in your now-bootable Windows 7 instance.
4) Copy the XP drive to partition Y. This should probably be done via an image backup, so that the file permissions will stay stable. If you just copy using your booted Win7 instance, I'm not sure what will happen to file permissions.
5) Use EasyBCD or BCDEdit to edit the boot table for Windows 7. Add your XP instance to the menu. You will now have a boot menu that will allow you to boot Windows 7 or XP from the big drive.
6) Put the old drives in a drawer for backup. If you leave them attached to the machine, it may try to boot from them - all three drives are bootable.
Thassit. The big issue is that one copy has to be a DISK clone, to get the boot sector. The second had to clone only the PARTITION, and leave the non-partition parts of the target disk, like the boot sector, alone. Then patch the BCD data and you will be able to boot either OS.
I have used this technique to dual-boot Win7 and DOS.