I'm moving from PCs to Mac. I've been really, really happy with Firefox and Thunderbird.
Should I stick with Thunderbird? V3 will integrate with Address Book and iCal, so I hear. I'm reluctant to move to Apple Mail when I've been so happy with Thunderbird all this time. But I can also see some advantages to Apple Mail...chiefly in integration with Spotlight, iCal, Address book, etc.