This is a comprehensive link:

http://en.wikipedia.org/wiki/Xilinx

VIRTEX-5

Virtex is ONE of the Xilinx current product lines - Kintex is a variant.
Virtex-5 (and -6) uses IBM Power-PC technology not ARM. Power-PC 400 series dates from 1999 and its core technology was also used in a wide variety of hardware.
http://en.wikipedia.org/wiki/PowerPC_400#PowerPC_440
http://www.xilinx.com/support/documentation/data_sheets/ds100.pdf

In its Virtex-5 FXT FPGA product line, Xilinx embeds up to two PPC440 cores.
PPC440 was introduced in 1999. IBM sold Power PC (PPC) 400 series technology assets to Applied Microcircuits Corp (AMCC) in 2004.
http://en.wikipedia.org/wiki/PowerPC_400

VIRTEX-7

The Virtex-7 is their most recent variation, introduced in June 2010 following an announcement by Xilinx in October 2009 they had made an agreement to incorporate the ARM "Physical IP" and specifically the ARM Cortex-A9 technology.
http://www.xilinx.com/support/documentation/data_sheets/ds180_7Series_Overview.pdf
http://www.xilinx.com/innovation/extensible-processing-platform.htm