My realm's considered medium population, but we've still got enough people that, if even 10% of the population typically online at server high time decides to roll a Death Knight once Wrath is released, Eastern Plaguelands is going to be in total gridlock for a while. The same thought occurred to a few friends, who wondered if they might be better off spending a week or two on low-level alts in an empty Azeroth while waiting for the furor to die down. With that said, that's not an ideal option if your guild wants to start raiding as early as possible, or if you just don't want to be left behind by guildies leveling to 80.
I'm genuinely curious. Let's say you've bought the expansion, installed it, and you're at the character selection screen on your usual realm with the option to create a Death Knight, hit your main, or head to an alt. Given your own personal circumstances, which do you pick, and where are you going in those first few hours?