Same re: the Linux version, though I believe it's still up in the air whether it'll even be released.
I've been lied a few times and will no longer pre-order, so this time I'll wait for official Linux release + at least 3 weeks.
If there's no Linux version, I'll keep playing Civ V. The only reason I switched to Civ V from IV was that I wouldn't need to reboot or use Wine to play it (and deal with the quirks of doing that). My excitement the day I saw that Civ V was available for Linux was massive.