It depends on the context. (Just so you know, in case you don't, "depend on whom" is the correct way to say it, but simply "depend who" is sometimes used very casually.)
Moocowsforever's response sounds better to me, because usually the context implies something other than a conversation going on right now, at this time.
"It depends on whom I talk to [next week]"
"It depends on whom I talk to [about the job offer]"
"It depends on whom I talk to [whether I get a good price]"
Compare this to:
"It depends on whom I'm talking to..." (which is certainly possible, but less likely, such as a remark to an unknown person in a telephone call)
Espero que sea de ayuda.