The lack of solos on Contraband was because Slash felt restricted. He wanted to save money and ended up recording guitars in some small studio where he didn't feel comfortable (according to his book).
Then Libertad was done with Brendan and everybody seemed happy because the band had played together longer.
So if Libertad was the best they can do, why would the next album be that different?
Rick Rubin wanted them to write more songs, they didn't want that. They wanted to record the stuff they had.
Considering 2009 is about 14 months away and they have some tours to finish, it doesn't seem like they'll have much time to work on an album if they wanna get it out in early 2009.
First off Slash said that there weren't as many solos as there could have been on Contraband because he felt restricted in the studio and wasn't as comfortable playing. Saying "the lack" makes it sound like there's hardly any, which isn't true. He also said he was happy with his work on Contraband.
Also your quote about Libertad being the best they can do is pure nonsense. Show me one quote where anyone ever said Libertad is the best they can do. I'm sure you'll have a ton of trouble finding one. They said they wanted to make the best album they ever made, and they also said that they were happy with the way it came out.
Also, they have plenty of time to get working on a new album if they want it out by "early 2009". Early 2009 would be anytime before April (splitting the year into four quarters), which is 17 months away. If you think that it'll take Velvet Revolver 17 months to do some touring, write a new record and put it out you're insane. If they wanted too they could have it out sometime in 2008, but the band probably doesn't want to commit to that constant of a work schedule.