^ it's not that there's no love for that idea, it's just that its not very likely. It's probably a quarter of a century since he last did UK TV. I think his last US TV appearance was in Friends, which always attracted big stars.
I think for the most part, people are thinking about who is likely to appear as well as who they'd like to see. Of course Oldman would be a great Master - probably a great Doctor too - but I'd say there's virtually no chance of him doing it.
I agree it's unlikely. But these days, Who
has gained serious attention, and can attract big actors for limited engagements. They got Derek Jacobi, who admittedly isn't as
big as Oldman, but he's still big. Known internationally, and has essentially "moved beyond television." Not to mention Ian McKellen or John-flipping-Hurt. So Oldman is unlikely
, yes, but not
out of the range of possibility.
Anyhow, who I'd cast as the Master would depend very much on how Capaldi plays the Doctor. However you see the Master vs. the Doctor -- "Mirror image," "dark reflection" or "similar traits turned up to eleven" -- it depends very much on the Doctor's performance and we really have no idea how Capaldi is going to play him, except that it certainly won't
be either exactly like Matt Smith or Malcom-Tucker-in-the-TARDIS.
If he's a calmer, more reserved Doctor along the lines of Pertwee or Eccleston, I'd rather see a demonstrative, aggressive and flamboyant Master. Someone like (but not) Eddie Izzard maybe. If Capaldi is more a "young heart in an old man's body," then go with, I dunno, Robert Lindsay.
For me, Cumberbatch only
would have worked as the Master against Smith, and I'm very sorry we never got to see that happen. Cumberbatch playing a very reserved, stoic, contemplative villain with the occasional flash of insane, dark rage would have been a perfect counterpoint to Smith's loveable, affable frenetic awkwardness.