[shinratdr]

I'm pretty sure with enough voice data you can make people say just about anything, and Tupac left behind a ton of voice data.

[JonnieCache]

Yep. See the work of cassetteboy: http://www.youtube.com/watch?v=_m2pFYYEiko (NSFW language)

All they use is soundforge, and it's trivial. You can achieve perfect results with modern software and algorithmic assistance.

[gpmcadam]

Wouldn't it be easier to just hire a voice actor or impersonator?

[ux_designer]

They did use a voice impersonator.

[murki]

source?

[shinratdr]

It would be easier to just sit at home and listen to an old Tupac album also.