According to a list of this week's European eShop releases, Mega Man X2 will be available on the Wii U Virtual Console this Thursday for €7.99 / £5.49. As per usual, if you downloaded X2 on Wii, you can score the Wii U version for a discount.
Hopefully the North American release isn't too far behind. Mega Man X2 is the last title to hit the Wii U Virtual Console in Japan. Let's hope we'll finally get Mega Man X3 next.