Unpopular opinion: Corey Burton's rendition of Ansem the Wise in Birth by Sleep is by far my favorite VA for Ansem the Wise/DiZ in the entire series.
And since Christopher Lee will undoubtedly be preoccupied with The Hobbit for the next couple of years, I'd welcome Corey Burton as long as he continues to VA like he did in BBS.
I'd love to see/hear him in DDD at some point.
Likewise. :3 I mean, Christopher Lee is utterly fantastic, but Burton nailed the Blank Points speech IMO, which is the most defining moment for Ansem to me. :3
I suspect Ansem might pop up in DDD via the data he encoded into Sora's heart. Maybe a recorded hologram, similar to that which he left behind for Roxas in KH2?