I think Williams will get back to the leading edge agasin, but not this side of VW getting involved in the sport, as ive been having a look at motorsport aliances and from what i can see, and feel and read into. It is in my opinion that we will see a Audi badged engine in 2013 for 2 teams, Williams as the two are linked in Formula 2, Williams design and build the chassis and Audi provide the power train. But the thing is that Williams are providing Porsche with KERS for their GT programme, so id expect a Audi branded engine in F1 to carry the Williams Flybrid KERS system as well.
I think this is the only way for Williams to get back to the front with a works engine. Thay came close with Toyota, but the Toyota was 0.3 tenths down on the opposistion, with the Williams FW30 and FW31 at the hands of Rosberg could have done dammage at at least half a dozen races in those races.
I think if Williams also get some quality sponsorship as well, and with the falling cost of F1, i think if williams get good investment and works power, with their buisness plan with both Frank Williams and Patrick Head and their wise heads leaves Williams a way to the front again.
One thing they need to do is stop the brain drain to other teams for their tallent in their design and aero department, this is the one area they need to stop first by getting their design team on long term contracts with a stong designer at the helm. If i were them id ideally go for either Pascal Vasselon (Ex-Toyota) or Geoff Willis (Hispania/Dallara and Ex-Red Bull/Honda) for their head man and then build from there.
I always have hope for Williams, but in the short term i think there isnt much hope, but in the medium to long term, it could look good for them.