I haven't commented here yet, but I've been browsing for a little while and am (and have been) very excited to read these cards, especially with all the comments I received on my own fan cards. I'll go backwards I suppose.
Plantation is certainly a new flavor, even from the other cards in this set. The separation of the effect by a season either way is a nice touch and the instant season-change appears well matched with the card's effect. One thing I think is unclear is where to put the marker; does it go to the beginning of the season? If it's moving exactly 5 spaces, I personally would prefer to say "5 spaces" instead.
My only concern for Timberland (B) is the learning curve. The effect and mechanic are exciting and worthwhile, but would there be much AP before the game trying to estimate which season it will end in, then planning accordingly, then your plan effecting your estimation of which season it will end in? What about some people knowing how many rounds an average game will take and some people not. This could be a non-issue of course. I'm sure there are people which will either buy it or not, independent of how long the game might take, and just one game with a Season card will give players a ballpark of how long a card will make a game. I might change my mind if I would actually play with it, but that was my first impression.
I think the current order for Student is appropriate, especially considering the drawback of not beginning in Spring. Worker's Village is still a fine consolation prize for missing Spring. They say hindsight is 20/20. I think the comedy of trying to put all the counters on one pile is incentive enough to buy the card. It's almost too bad you didn't fit the Trashing and Journey tokens into it somehow. XD
I have to say that I'm surprised that, in all the discussion of Trade Port, and all the comparisons drawn, nobody described an interaction with Throne Room. If you compare anything in the scope of Throne Room, I'd say that Trade Port is clearly worse. You have only 1 chance for Throne Room and Trade Port to collide, and even if they do, you lose the Throne Room. With the non-terminals previously compared to, you're likely to have many [card] to easily collide with Throne Room, and you still have the Throne Room to use in other cases. Especially with the cantrips, you get your 2 played cards replaced in your hand, split actions, and whatever other bonuses, but with a Trade Port, you lose the Throne Room, your current turn is just 3 cards, and you've gotten 1 more coin per turn - unless you were actually going for 3 buys per turn. Either way, it would be way better to actually get a second Trade Port instead of trying to Throne Room it: you still lose 2 cards, but they don't have to collide, and you still get your 2 coins and 2 buys. Am I way off base here?
There isn't much I can say that hasn't already been said, and I don't feel like starting a vote.
I'm also curious... at the beginning, 12 or 13 cards was the set size, but if this is the last card, then we only have 10. And what of this mysterious Event we heard of? Perhaps you were just being literal by saying it was the last "card" and the event will still show up, but were the other 2.5 cards so bad as to be cut before there was any feedback? Perhaps it's merely an Alchemy situation and the remaining two aren't Season type, but will still show up.
Are you still looking for TTS players?