Of course we can download information directly into the brain... I mean, they did it in the Matrix.
At first glance there doesn't seem to be a reason why we wouldn't be able to. If we assume that brain functioning is only dependent on the flow of electrons in the neural networks of our brains, then in theory we could implant electronic devices that code the algorithms necessary to do a certain task, or have a certain memory etc., and have the devices interface with the existing organic network. (The logical extension of this, by the way, is mapping out the entire brain and all its algorithms and simply replacing the organic substrate with a duplicate electronic substrate. Of course, then there are issues of neural plasticity/adaptability/learning, which would involve encoding genetic information that governs how neurons change, grow, and interconnect/deconnect over time as well. This has been the topic of some interesting science fiction; see "Closer," a short story by Greg Egan.)
The true picture is probably not this simple, though. While all our brains possesses the same overarching structures (such as visual cortext, motor cortex, language center, etc.), on the level of individual neurons we probably encode information quite differently. So while we might want to, say, create a vocabulary chip and implant it in our language center, we would probably have to customize the chip to each individual person. To do this we would have to crack that person's 'neural code' (how their brain encodes information on the level of neurons), which (as you could imagine) would be no small order; with current (and forseeable) technology and understanding it's a hopelessly intractable problem. And even this is an oversimplification; it's not enough to understand how a person's language center works in and of itself, because you also have to figure out how it interfaces with the temporal lobe (sounds associated with words), occipital lobe (pictures associated with words), hippocampus (memories associated with words)... etc etc etc. Basically you would have to figure out how a particular person's brain works in total before you could really do something effectively and seemlessly like this. Science is making great strides in figuring out the brain but the discipline is really still in its infancy if you ask me.
There have been successful implants developed already, but these only function on the level of gross input (eg to assist in the channeling of information to the vision or hearing centers). Getting the information into the brain isn't that complicated, but manipulating the information once it gets there is a whole other story.
As for the philosophical implications... I don't see anything wrong with brain modulation in theory, but in practice it's probably a can of worms best left untouched, at least until our basic societal attitude gets a radical makeover. It won't be long before they start putting chips in milk cartons and tracking your every purchase... picture a gigantic database owned by a faceless entity containing the smallest minutia of your life, down to what kind of potato chips you like. That alone is scary enough... who knows what kind of things they could do once they can crack open your skull.
