Edited this one to point to the correct episode — it was 15, not 14. Oops.
I was listening to episode fifteen of Yo! MtG TAPS! while I was in the lab for a couple hours this morning, and after showing great restraint at not turning them off when the Jund complaining started, I started jotting down a few notes relating to the content. For those YMT! listeners out there (and I do enjoy the show, so you should go give it a try), here they are:
1) One of the concerns people naturally have about Legacy and the inability to reprint dual lands is that if Wizards were to go ahead and print functional replacements, players who currently own duals would still be advantaged, because they’d be able to run eight of a given dual.
This isn’t actually as big an issue as you might think. Consider the use of duals in the following tier one Legacy decks:
Ad Nauseam Tendrils (ANT)

• 4 Underground Sea
• 1 Tropical Island

This deck could happily replace that one Tropical Island with our theoretical Snow-Covered Underground Sea (I love tacking “Snow-Covered” onto all these card names to yield curious-sounding lands…).
Belcher

• 1 Taiga

Some Belcher lists run two lands. Clearly, we’re not coming close to dipping into extra duals on this one.
Countertop Progenitus

• 3 Tropical Island
• 2 Tundra
• 1 Volcanic Island (with one more in the sideboard)

Once again, we’re not dipping into extra duals. The mix of Tropical Islands, Tundras, and Volcanic Islands is necessary to make the deck work, rather than being some kind of concession to availability of duals.
Dredge
None. Legacy Dredge in its various forms does not use duals at all.
Reanimator

• 4 Underground Sea

This deck could run additional Snow-Covered Seas, but that’s probably a bad idea, as it increases your vulnerability to Blood Moon effects (which is probably why you’d want to run multiple Swamps and Islands in the first place, as the current lists do).
Zoo

• 2 Taiga
• 1 Savannah
• 3 Plateau

In Legacy or Extended, Zoo decks just tend not to max out on specific duals.
In the fetch-laden land of Legacy, most decks don’t run the full complement of any one dual, and thus wouldn’t benefit at all from having access to “four more” of a given dual. There are some exceptions, such as ANT dipping into a “fifth” Sea, and possibly Goblins, but generally, decks in Legacy do not automatically improve with access to four more of the same dual.
2) I’m still going to have to disagree with the view of Jund. The NFL analogy is off — having six Jund decks in the top eight of a GP is not the same as having the Patriots appear over and over again in the post-season, because the differences between any two Jund decks are much larger than the differences between, well, the Patriots and the Patriots. I’ve written about this more than once, but just looking at the colors and the presence of Bloodbraids and saying, “Oh, Jund again” is a lot like grouping all the AFC West teams together as if they were the same superteam.
Essentially, if you’re not going to bother to track the major differences in builds and pilot skill, then yeah, it’s going to seem like more of the same. That feels like almost intentionally making the game more boring for yourself, which is part of why it bugs me a bit each time I hear folks do it.
Or, put more positively, the difference between Gortzen Jund and Reitbauer Jund is significant and cool. It’s like watching the differences between the various Teachings builds at PT Yokohama, which ranged from single-card-choice differences through whether to include the Pickles lock or not.
3) The top eight at Kobe not being coated with Affinity decks and the idea that Affinity was dominant at the time are not mutually exclusive. It just shows that some people made an excellent metagame choice and, along with their play skill, piloted decks that were tuned to beat Affinity and have game against anti-Affinity decks into the top eight.
Here was the day one breakdown at Kobe:
Affinity – 110
Green-Red “Anti-Affinity” – 44
Big Red – 39
Mono-Green – 16
Death Cloud – 12
TwelvePost – 8
W/x Control – 5
Other – 6
None of the Death Cloud decks made day two, and only one W/x Control build (played by Shota Yasooka) made the cut.
Here was the day two field:
Affinity – 38 (34% conversion rate from day one)
Green-Red – 13 (29% conversion rate from day one)
Big Red – 22 (56% conversion rate from day one)
Mono-Green – 8 (50% conversion rate from day one)
Death Cloud – 0 (0% conversion rate from day one, and weren’t they sad about that…)
TwelvePost – 5 (63% conversion rate from day one)
W/x Control – Just Shota (20% conversion rate from day one)
One of the issues here, of course, is how we define “dominating.” The default anti-affinity R/G deck did rather poorly, but as Affinity was also the “I can’t think of anything better to do” choice for many players, it had its win percentage brought down by, well, bad players and people who just didn’t enjoy playing the deck. We saw something similar at Pro Tour San Diego this year, where 112 players brought Jund, many while saying they didn’t like the deck, but couldn’t think of anything better. 45 Jund decks made it to day two…which doesn’t tell us as much as it used to, with the draft rounds.
Affinity was “dominating” much as Jund is, in the sense that a good Affinity build with a solid player behind it would be very hard to take down. That said, it’s also “dominating” in the way Jund is in simply being prevalent, which means that many people have chosen it as the “best deck” without really understanding how it works or how to play it optimally. As a consequence, good players running other decks can carve through much of the field and make it to the top, much as we saw in San Diego this year. Consider the top eight constructed records from San Diego:
Luis Scott-Vargas, running Boss Naya
Jeffrey Chen, running Vampires
Tom Ross, running Boss Naya
Aras Senyuz, running G/W Reliquary Angel
Gaudenis Vidugiris, running Mythic
Pat Chapin, running U/W Control
Bertil Elfgren, running Siege-Gang Jund
Jason Ford, running Bit-Blast Jund
Despite the ho-hum response of “Oh, it was Jund in the finals” that people had, our top constructed list comprises six different archetypes even if I go ahead and batch the two Jund lists together. That’s significantly more diverse than the Kobe top eight, which was five Big Red decks, two Affinity decks, and one copy of TwelvePost (although in fairness, it was Block and thus bound to be less diverse).
I don’t have a huge conclusion on this one except that there are two meanings of “dominating,” and they tend to feed into each other. A good deck dominates to some degree, and then becomes prevalent…and thus becomes “less good” because so many people who don’t understand it, or perhaps don’t like it, are trying to run it.