So, everyone is aware of the
Native Village/Bridge mega-turn combo, where you build up a huge Native Village mat and cash it all in for a boatload of Provinces on the last turn, using the stored draw of Native Village to get lots of Bridges in your hand, and have the +Action to play them all.
Well, Horn of Plenty is another card which has similar mega-turn potential with Native Village, as seen in this game I just finished:
http://dominion.isotropic.org/gamelog/201204/02/game-20120402-144850-fccaf6e3.htmlObviously, HoP/Native Village is a little trickier to pull off, as you can't just mindlessly buy the two components, you do need to pick up enough other pieces to boost your Horns to $5. And since HoP is $5 and not $4, getting it started is possibly a little more difficult. However, as long as those two cards are in the kingdom, there is clearly mega-turn potential. HoP, NV, and Copper/Silver/Gold gets you to five unique cards already, and the +Actions of Native Village ensures that no matter what else is on the board, you can find three other cards to help you on your way to $8 Horns. The other cards were actually pretty weak here; Chancellor and Talisman are not the sorts of buys that strike fear into the heart of your opponent, but they were good enough to get to $8. The Oasis and Cellar were actually more crucial, the Oasis providing cycling and cash, and Cellar was used once to ensure that I got all seven of my Horns in hand for the final turn. There really wasn't any reason for me to buy a Wishing Well, I was just upping variety to make absolutely sure the Horns would max out.
Getting to start $5/$2 was a boost in this game, but even 4/3 starts should be able to transition into this deck well, probably opening Silver/Silver-equivalent and then picking up lots of Natives and Horns starting on Turn 3. As for counters, my initial feeling is that this combo should beat most other strategies, but it's not quite as dominant as NV/Bridge: it should be beaten by strong cursing, Goons engines, and Ironworks rushes at least. (Though if there's good trashing about, NV/HoP can probably handle most curse-givers). Of course, except for something like Ironworks/Gardens, you can likely add NV/HoP to these other elements, you just can't ignore them like you might be able to for NV/Bridge.