I think they should do both!

It would be really bad for them not to include the classic TOS BoP at some point, but part of the fun of this collection is going to be getting ships that haven't yet been released elsewhere. I'm really looking forward to getting some of those ENT designs! (I'm even still hoping they can somehow get authorization to release the unused "D4" as a subscriber exclusive or something!

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I totally agree that they should do them all eventually.
I really hope the sales do very well and they would someday even release some novelverse ships. I would love a Titan and an Aventine model.
While it's not totally unheard of to get miniatures from the books (Galoob ventured into that a little bit with Star Wars), I think that's kind of a long-shot, what with Star Trek sticking to the "novels aren't canon" rule pretty faithfully over the years.
Hey, if they set does REALLY well, you never know, but, best-case scenario, they'd be pretty far down the list.
And again, that's a long shot.