Deathrow,
FO's are perfectly capable of handling emergencies. They wouldn't make it past the simulator phase of training if they were unable. In fact, at least one major carrier in the US stipulates that the FO will be the pilot flying in case of an emergency.
This makes it easier for the captain to go make the decisions, and I suppose the radio communication will be a teeny bit faster, which could be critical in a few situations. From what I'm told, a few pilots were skeptical at first, because it goes against the grain of what we've commonly been taught, but they find that it works very well. Never done it myself, but I have to say that the theory does make quite a bit of sense.