I don't think I would call it a comeback. As I just mentioned in another thread I just started, with the Tournée no more, they both lost what I'm sure was a nice little pay check each year. Plus they lost the fact the show keeps them in the lime light. I think that's what these appearances are about. Some income yes, but also to keep them in demand until other opportunities arise.
As far as a band, I'm sure she has enough connections to get her a decent band. I'd be happy with just a couple of guitar players as was so typical of her early career.
One thing I don't want to see is bunch of girls on stage with her like we had with 'Hung Up' performance...
When Alizée is packaged right, there's nothing else you want to see on stage. That is still true today. There's nothing else that needs to be on stage. But that is something she's had a huge problem with since leaving MF. She looks great off stage and terrible on stage. If she looks terrible this time and she's a little rusty in voice, it could spell big trouble for her. If she dazzles them with her looks, they might be more forgiving if she's off in other areas. It's a no brainer. She needs to look her best.
From what I'm hearing it will be I would think at least a half dozen songs. They have her scheduled into a 2 hour block, so I doubt if they would bring her in for just 2 songs, but as her past festival appearances have shown, one or two is the norm so who knows yet?