50k ft view -
This expansion needs to launch, it needs to launch sooner than later. Giving a hard launch date is the best thing they could have done.
Will it be ready for launch in 2 weeks? Yes, most likely; given the proper definition of 'ready'.
Looking at the elements of the launch in relation to preparedness.
Bugs - No, this launch does not have to be completely bug free. Issues that make the ENTIRE game unplayable must be dealt with. At this time, the only known one seems to be the video card issue; as example. But also, any new bugs introduced into the existing alpha and beta mechanics, and any new mechanics associated with that play, like factory and mining.
PVP combat Balance changes - the only real change is the introduction of the new Ewar/neut modules. When have any new modules been 100% balanced at release? As long as the devs keep a close eye on this they can tweak them as needed, with only a slight impact on the overall PVP play. (And they've already got some good feedback in the ew thread).
Industrial Changes - These are tricker, since they are sweeping changes. But again, the balance doesn't have to be perfect. There's enough 'wiggle' in industry that if they get the material and time production values off (even by as much as 20%) it won't be the end of the world.
Gathering Changes - There's a difference between making changes players don't like and making changes that are bad. Mining is one of those, that again has gotten a lot of input already, and if players simply hate the new random ore mechanic, their input after it goes live can still make a difference. As long as the ore isn't actually bugged, it won't break the production cycle; as long as miners can get the ore the balance can be adjusted, even if they don't like doing it.
Gamma/Coloney system - Realistically, what percentage of the player "current" base is going to be able to fully utilize and build on gamma? Not many. And the 'draw' of this capabilty for new players is large, but unless they get recruited into existing corps, they too aren't going to be participating in gamma any time soon after release.
Will there need to be balance changes, absolutely. Could they possibly think of and make those changes without going live? Unlikely. Even with another 2 months of server testing.
As for costs and rewards - Just like in any sandbox game, the Mantra
"Don't risk what you can't afford to lose"
MUST be applied to gamma too. We've been given the opportunity to see how well base defenses work, if a corporation or alliance chooses to ignore the PTS opportunity and go in blind, then that's an Unecessary additional risk. If they have, then they'll know before hand how many players they'll need to supplement their defenses. If they don't have enough, then they should consider not trying to build a Coloney.
50k ft view again - It's up to the players to create with the tools we're given. As long as they work correctly, we're going to have to put them into action to see how they do. Near launch, someone undocked in a Prototype mech and got blown up. Should the devs have put a mechanic into the game that prevented them from doing so, simply because it was a terrible waste of resources? No.
Players are very excited about gamma, and rightfully so, and they want to jump in there and explore and use the new system. But we all know going in, that there will be losses, that automatted defenses can't fully protect a colony, and that some tweaks will be made after release. Don't build what you can't afford to lose.
Just because something new is added to the game, doesn't mean that it should be scaled to allow players to use it immediately.
tl;dr - As long as the Colony expansion is VERY functionally stable, and the major balance issues such as 1000m TF are caught, it should go live. Base defense has too many elements to fully test balance issues on PTS and is highly dependant on corp/alliance size. Players simply need to exercise the same judgement with gamma as they would with undocking any bot.