How far does brand loyalty go?

I've always thought of the Mac vs. PC conversation as something bordering on religion.
I used to work with a team of graphic designers that had a picture of Bill Gates on the wall with added horns and black teeth and had major hissy-fits when asked to open MS Word documents; they saw this as a betrayal of everything Mac.

Likewise PC owners have traditionally viewed Mac supporters as weirdy-beardy muesli-eating creative/geography teacher types.

Take the recent adverts from Apple. this did nothing to ease the situation.

Now lets talk iPod vs. Zune. Apple has 80% of the mp3 player market and MS has just under 4.5%; it's the David and Goliath ratio flipped on it's head.

Buying an iPod is completely acceptable to a PC owner because Apple has got it right. By all accounts the newest of Zune players are merely equal to last-generation iPods so I can't see any Mac owners making the switch just yet.

Brand loyalty only goes so far...