A couple thoughts come to mind, though, about next weekend's episode:
first, if they go to the alternate dimension, shouldn't the TOS guys have been able to figure things out a little easier, and probably known what they were dealing with in the original alternate universe episode? I mean, seriously, you think that something that bizarre wouldn't show up in the history books with more than just a slight mention?
Also, finding Defiant, wouldn't the same thing apply? I mean, when it disapearred, they'd already know where it went, right?