I really have big hopes for this years Vuelta. Normally my favourite GT is the Giro, because it always was a Grand Tour for climbers like Simoni, Cunego, Di Luca or Pantani. This year the Giro was specific to Lance Armstrong, with not as difficult mountain stages as in 2008, 2005 or 2003. But if I look at the stage maps of the Vuelta, I think the Vuelta could fill this gap this year
I don't think that we have a clear favourite for the overall win this year. Contador - if he's going to ride - will be perhaps exhausted from the Tour and will lost time on some mountain stages.
Valverde in the past always had one bad day where he get's a bump, in every GT he was riding , like in last years Vuelta or 2006 when he lost the Maglia Oro to Vinokourov. So I think he won't win a GT again.
Sanchez is a very complete rider, but not the strongest climber. But he has focussed his whole season on the Vuelta, and will have a super-domestique with Igor Anton. Perhaps he will profit from Valverde and/or Contadors failling.
Basso can't win a GT any more, if you ask me. His attacks at the mountain stages in the Giro have all been blown out, he isn't as good as Sanchez or Contador in the TT any more. But perhaps he is better "prepared"

than in May and could go for the Podium.
Gesink is my big hope this year. 2008 he was a fantastic 7th in his first GT ever. At Dauphine he looks very good, ending 4th behind Valve, Evans and Conta and would have shown some strong perfomances in France, if he wouldn't have been retired. Now he didn't lost energy at the Tour, if he's back at 100% after his Training in St.Moritz he could be the big suprise, going for the overall win and the red jersey. Although he's only an accetable time trailer. I hope Rabobank will give him strong support with Garate, Weening, Ardillia and/ or Mollema and won't be focussed to much at Freire.
The big question mark maybe is Mosquera. Last year he and Leipheimer have been the only ones who could follow Contador in the mountains, after the retirement of Igor Anton. But he's the worst TT of the favourites and he hasn't got a strong team in the mountains. So it would be very hard for him to place at the podium this year.
Evans will ride the Vuelta too, and if he's in good Form he is definatly a candidate for the podium. For the overall win he may be not good enough in the mountains. He's more a type like Mentsjov or Ullrich, not a great climber like Contador or Sastre that you need to be in this years edition.
Moncoutie may try to place in the Top 10 again, after a dissapointing Tour, and look for a stage win in the mountains.
Would Astana have a second ace like Leipheimer last year? Zubeldia for example or Chris Horner who performed well in Giro until he retired. And don't forget Klöden of course.
What's which the other wildcard teams, like Vacansoleil or Andalucia. Do they have a man for the top 15? Is Gomez Marchante of Cervelo a man for the classement again, after years of injuries?
Vacansoleil could set some accents in break aways with Leukemans for example or with Baden Cooke in the sprint (if they gonna ride). Without Cave the fight for the sprint wins and the points classification will be very interesting with Freire, Greipel, Van Avermaet, Rojas, Cooke e.t.c
So it's all given for a exciting Vuelta this year if you ask me.