Issues:
1) Pressing Shift and 3 on a Mac doesn't create a £ sign, as it would be expected to do
2) Sometimes when switching between applications using cmd+tab and back to minecraft, pressing the backspace deletes the words even when the cmd key is not being pressed. You need to hold cmd and tab for about 2 seconds with chat open for this to happen.

Neither of these issues are present in version 1.5, and both these issues only happen on macs.