Ive thought about this for years, and let me start with some points IMO:
1. Janet's story aint over, so even now a biopic would be kinda premature, my only reservation I dont want her story NOT told because no one's interested, and that's all timing. Lena Horne who? To this generation of kids out here.
2. I dont see a single female that would play Janet convincingly, through all the different eras, different looks, and "size" one of the hallmarks of Janet's "brand" has always been her looks, which is why Janet when acting has its issues because kinda hard not to see her and think JANET.
3. Depends on the script. If you can pull off another "What's Love Got to Do With It" I would be in, that movie was well produced.
4. I'd rather Janet do her memoirs or autobiography, she tends to be more candid in print. If a biopic were green lit, I wonder how much more would she be willing to tell? I mean if we hear about the key to the animal cages, or not keeping a journal so my songs are my journal, I will scream in the theater "stop" run up in front of the movie screen and scream "Give me a beat!" *thinking about Voodoo*