If it's going to happen they'll probably keep it just a rumor until they've had a decent run with the cupra, staged release of the top end models to encourage sales.
I'll be looking to upgrade my Tdi in probably 2.5 years so if a 4wd version is out then I'd seriously consider it, hopefully it can be reliably/easily tuned to the 300bhp mark, and able to keep the power on the road due to the 4wd. Something that you can have fun with on the track, I've only had the TDi 6 months but already missing a car with some decent power.