Syp has a bit of a parody of Cryptic's latest promotion for Star Trek Online. By paying $300 for the game plus a lifetime subscription (offer expires before the official retail launch), you can secure the right to play the "Liberated Borg" race for the Federation.
Cryptic hasn't explicitly stated that the Borg race would never be available via any other means. Even so, this seems like a slightly dangerous road to go down as a pre-order bonus.
Would players who are interested in the game decide not to play because they were unable to choose a race that has played an iconic role in the game's lore? Perhaps not. Then again, playable races are often the headline features of paid expansions. If nothing else, honoring the spirit of this pre-order offer would seem to preclude having a playable Borg expansion down the line.
On the other side of the equation, though, how badly would it erode confidence if this feature trickles out to the playerbase at large at some point? Cryptic is presumably planning on item store sales as a major portion of STO's revenue, and players may regard the next limited time offer with far greater suspicion if exclusives like the Borg (or the "Joined Trill" race, of Dax from DS9 fame, which is exclusive to some digital "deluxe editions" of the retail game) make their way into the game at large.
Perhaps this promotion will sell more lifetime subscriptions and therefore turn into a win for Cryptic. That said, this evolution of the high pressure pre-order sales pitch sounds like a lose for players. I can't think of any precedent for an MMORPG restricting access to a player race like this, much less a licensed game (where the licensed races are a major selling point of the IP). All that changes in a few weeks, and time will tell how it plays out.