Evolutionists, how many years until cats can speak human languages and become scientists?

The year 5,000,000,023 on New Earth, in New New York. They will mainly specialise as nurses.

For the sake of others reading this question, I'll pretend the question is serious. Cats never will unless they choose to. Humans began to diverge significantly from the other hominids and primates when they chose to emphasize intelligence, communication, cooperation, and teaching their knowledge to their offspring. Cats have no reason or motivation to do any of that. They do just fine in their present niche.

Dolphins and related mammals have relatively high intelligence but lack effective means to use it. We walk upright, freeing our hands to manipulate our environment. The opposing thumb made us very capable of doing that. No other apes made the choices humans did. They generally stayed in their rich environment where they could survive with very little work. Some people think that way now. But humans ventured outside regions of easy survival, so they had to work at it. I think chimps and some of the great apes could learn human languages and could further develop intelligence, but generally they don't care to. If they did, it would probably take them of the order of 100,000 years to catch up to where humans are now. I don't think humans will stand still, so I doubt they could ever catch up.

Evolutionary theory does not make the prediction that cats would do any such thing. As is so very very common, you have come up with a pretend theory of evolution that has nothing to do with reality, and you're attempting to make it look foolish, in a misguided attempt to imply that therefore, the real theory is foolish. This logical fallacy is called a strawman argument, and it is used by people whose position is so feeble as to be completely unable to go up against reality, and so they stick to a fantasy world in which their beliefs have some chance of being true.

Not in the foreseeable future. There would need to be very specific cirucmstances promoting selection pressure to develop much, much higher intelligence than they have now. No such situation exists for cats right now.

That makes no sense. Cats are not "behind" humans evolutionarily speaking. Every organism alive has made it this far, they are all equal. Cats will never speak. Cats diverged from humans millions and millions of years ago.

I reckon it will be the day after any creationist actually demonstrates some understanding of the theory in which they claim to disbelieve.

How can you not believe something you so obviously don't understand? All you are demonstrating is profound ignorance and lack of education.

What is the selective pressure to cause either Felis or Panthera species to develop that trait?

The answer is most likely never, and I hope you don't think evolution means humans came from monkeys.

-As SOON as the Creationists go Extinct...- Any time after the next 20 Years or So. :)

Either you're a troll or you have no idea what evolution actually is.