I doubt that VW will pull the plug just yet. They've put a lot into the Polo program after moving the funding over form the Dakar program. VW didn't court WRC for a long time because the board operated under the allusion of trying to move the brand upmarket. With products like the Phaeton, VW wanted to compete with Mercedes and BMW. As far as things seem, and quite frankly, I think to the surprise of VW management, Audi was really able to move into that position where in the 80's, they were quite distant from the prestige of both BMW and Mercedes.
This actually worked out and allows VW to remain where it operate most naturally, as a slightly more refined alternative to the boredom's that are Toyota and Honda.
As such VW has begun to explore things like the TDi cup and now the WRC. Seems every year they are linked with a F1 rumor, but it never pans out and would not necessarily be a good fit for VW where it would for Porsche or Audi, although with their relative successes over the past few years, I am not sure F1 would be a benefit and may do more harm than good a la Toyota and Honda.