Seems like Janis is making a comeback in a big way. I recieved a phone call about this, this morning, that a new reality tv search is going to happen and they're looking for the new Janis to audition and tour with her old bands.
The press release
I spent some time at this site today in the message board and listened to quite a few women who are going for it. Some very good voices in there. Kristin Blondin does a tribute show, she was a close. Another women who sounded close was Deb Seitz.

This led me to check out the Joplin project- This is going on between two movie production folks and it seems the race is on to see who gets their flick out first.
'Piece of my Heart' would star Renna Zelwieger (spelling?). It sounds like Melissa Etheridge was up for this part but she backed out because of the long delay in making the flick.
The second production, and I can't remember the name, they are talking of using Pink. Pink would do most of the vocals.
I can't see where either of these women could do Janis, but even the contest is going to be interesting. Janis is a tough one to try to imitate if that's what they are looking for.