've always considered the weeks immediately before a new set comes out to be an excellent time to catch up on older formats that don't get as much attention when a new set has recently shaken up Standard. It never feels great to try to build a new Standard deck when new cards will be changing everything in mere weeks anyway. But larger formats like Legacy and Modern will stay largely the same, even if you can always count on some new cards to find their way into a variety of decks in these formats.
We recently had a Legacy Grand Prix in Denver, and it proved what a variety of smaller tournaments had already begun pointing to: that Jund is a real competitor in Legacy. It took a few years for the format to fully embrace Bloodbraid Elf, despite the card's dominance in Standard, but Pat Cox and Josh Ravitz both made it to the Top 4 of this tournament with three Bloodbraid Elves each.
This deck is a shockingly close port of the Modern deck—outside of the lands, there are only four cards in each deck (3 Hymn to Tourach and 1 Sylvan Library) that aren't legal in Modern. As for the lands, the players opted to use Wasteland instead of the man lands used in Modern to get extra spells out of their lands, a decision which is probably influenced by the prevalence of Wasteland in other decks, making man lands generally weaker (I'd probably still have tried to play one or two myself).
I've chosen to feature the remarkably similar Josh Ravitz list over the higher-finishing Pat Cox list because Josh had a single copy of the bizarre Legends enchantment Chains of Mephistopheles (yes, I had to read the card name as I typed that, and no, my spell checker doesn't like it). While this card is in play, any card that draws a card becomes basically uncastable. In a format defined by Brainstorm, that's a pretty big deal, especially since many decks that play Brainstorm also include cards like Ponder. This two-mana enchantment can easily blank eight or more cards in an opponent's deck and entirely invalidate some strategies, like the High Tide/Time Spiral deck. And the best part? Your card draw, provided by Dark Confidant, neatly gets around it, because the reveal and put into your hand action performed by that card doesn't count as drawing a card.
Josh Ravitz's Jund
Legacy – 4th, Grand Prix Denver