I've had several attacks on my Mac mini...not sure if any were successful, but, my Bitcoin funds in my encrypted wallet were just fine.
There are some very important security issues to figure out with Bitcoin. Ideally, clients would be able to employ physical keys that would make an eaves dropper with complete access to all the files on your computer and able to record every keysteoke unable to steal your coins.
This is an important concern.
Yes - it is definitely needed. Yubikey is good alternative, I am seriously considering that.
Pulling this off requires some practice. Yubikey is nothing more than a USB keyboard that comes with a subscription service. You can program Yubikey to present strings you specify off of their service, but when we get down to the grit a Yubikey is still a keyboard until you go out of your way to make it into something else.
