Why would it be?  From what we know about the brain it will do most of the work for us, all we have to do is learn how to format our input to the brain and it will do all the hard stuff..in fact it sort of has to as it is the point of interaction for the individual and the outside world..you have to let it interpret because that is how it "experiences" things.

The hard part is actually determining how to format the input and we aren't even sure if it would be the same for each person, right now it seems likely that the format will be mostly similar but with small variations from person to person.

I believe that the correct answer is:

Never.

 also possible.

Our computer technology will hit a limit if/when we go extinct. That's it!

when you will see better graphics in pc games than in real life :) you're playing some gta 18 game, see there some chicks, look at your super model poster on the wall and say "god this super model is fugly. how many polygons she has? 12" then we will see pc technology limit.

but .. its not weird all this computer thing is come in less than 100 years ???

Oh, also if a major economic or existential crisis happens. That would also count.

did my thread reach its limit lol.

I remembe watching a TV program about this quite some time back. It discussed a law that this person devised, I can't remember the name of the law or the person, sorry. Anyway, it stated that we should push for computers power to double every one and a half years and if we followed this rule we would reach the most powerful PCs we could manage by 2020. This meaning that each switch and whatnot is only made of a few atoms, we physically can't make them smaller. So far we have adhered to this law (more of a prediction IMO).

Anyway, this is nice to think about, but in practice things are different. Aspects such as quantum mechanics and nano-engineering all will have an effect on this. Another driving force is that of investors. We will always look for a way to have more advanced technology solely for comercial gain.

So simple answer = 2020
Real answer = Never

That's Moore's law, which is really not so much of a law, it's more like his prediction on the evolution of chip technology.

You are right that the current chip paradigm will hit a wall eventually, but as you said that's different from saying that PC technology will hit a wall. Notice that before transistors, we were using other technologies like, for example vacuum tubes or relays. Those technologies also improved exponentially until they hit a wall, but then they got replaced with newer technologies which also improved exponentially.

There are several new paradigms in the horizon which can potentially replace the current chip technology. Light-based computers are one possibility (the components communicate using light instead of electrons). 3D chips is another (several layers of transistors to allow for shorter communication paths). I'm not very knowledgeable about these new potential paradigms, but suffice to say that they are being studied, and one of them might prove to be the answer to the limits of the current paradigm in electronics.