The Harmonium wait was kind of frustrating--especially from a promotions standpoint.
Things kept getting pushed back and finally when they decided to push White Houses in early August the CD release was pushed back from October to November 9th. The reason for all the pushbacks was (I think) because they were trying to make everything perfect and make a good run with V because they were really hitting the radio trail hard, but things didn't really work out. White Houses sank on the charts, thanks to the lack of push on MTV/VH1 and the fact Interscope stopped pushing it after the initial radio push, Harmonium didn't come out until halfway through her promotional tour for it, and the CD leaked on the internet 2 months early and killed pretty much all the hype for non-fanboys.
There were a lot of expectations on Harmonium because of the fact it was her sophomore CD, and there was a 2 1/2 year gap between CD releases, which pretty much made people in the mainstream forget about her. With the lack of promotion by A&M, the album didn't do well in the mainstream. I think the focus for VC3 will be more towards the core group of fans, but at the same time will kind of try to regain some of those lost chances from Harmonium.
... and just with the potential songs for VC3, I wouldn't be surprised if a couple don't make it. I know at one point Vanessa said that Swindler was going to be on VC2 (ie: Harmonium), but it wasn't. And I think Morning Sting was going to be on Harmonium too, but it didn't make it either. Just something to keep in mind.