But then there's those darn duals. You can't reprint them, but you need to run them. We can reasonably assume that Wizards wants a popular Legacy format, and as it increases in popularity, players will want more duals. This will absolutely increase their price to a far greater extent than Jace/BSA/Gideon/Elspeth will hit in T2. So what are the possible solutions that Wizards could offer?
1. Ban Dual Lands and make new ones
This one is a bit extreme and would necessitate a good Dual replacement. Ravnica shocklands would not suffice; Goblins, Zoo, and even Burn would all too eagerly take advantage of the repeated free Lightning Bolts over the course of a game. The problem is, these lands would have to be good enough to replace preexisting Duals and keep the format stable, but not too good so as to mess up Standard and Extended. That means they would need to be a) Fetchable and b) resource friendly. It also means that these Lands would need to fit with modern Land design philosophy as outlined by Rosewater here:
http://www.wizards.com/magic/magazin...com/daily/mr65
Yeah, some of that has been broken (Dark Depths anyone?), but for the most part, new Duals need to adhere to these ideas. That's bad news for Legacy. For one, the Lands can't be "strictly better than basic lands". Don't get all Wastelandy on me; in many situations, Duals are better than basics, and this is absolutely true from a design perspective (Rosewater's and co.). To do this, lands need to have drawbacks. Rosewater points to a list of possibilities. I will briefly address this list in regards to Legacy.
A. Tap for colorless: Doesn't fix mana, so not a real Dual.
B. Comes into play tapped: Too slow.
C. Requires life payment: Disadvantageous against Aggro. Ravnica shocklands were the paragon of B and C combined, and Wizards is not going to improve on that much. As discussed, those lands just won't work in Legacy.
D. Use every other turn: Even slower than coming into play tapped.
E. Limited number of uses: This is actually a realistic option. A "Gemstone Mine" cycle of duals would be feasible in Legacy, but only in Aggro and Combo. Control decks would find these lands quiet prohibitive. These would also be pretty darn useless in Standard (a much slower format).
F. Cost required when land is played: Depending on the cost, this could be alright. Something that forced you to Exile a certain number of cards from your graveyard, discard a certain kind of card from your hand, pay a certain strange cost, etc. would be useful in Legacy archetypes that could actually pay that cost. Unfortunately, this would exclude a lot of decks that could not pay the cost, tipping the format towards those that could still use Duals (remember, the original Duals have been banned in this alternate universe).
G. Don't provide mana by themselves: Slow, too vulnerable to Wasteland/Stifle, too clunky.
H. Requires another permanent in play: Again, too prohibitive of a design. Only certain decks could reliably use certain color lands.
At the point in time where Wizards is shaking up the Dual lands of the format, both with bannings and printings, the Legacy format is already getting a serious facelift. At that point, it might be better to just move on to a new format instead of trying to apply Magic the Gathering's largest band-aid.
2. Ban Duals and print no replacements
I imagine this idea would not fly in most Legacy circles. Lots of decks would change, perhaps even be crippled. Monocolor strategies would endure, as would fast Aggro strategies that could ignore the loss of life for running more costly duals (whether fetchable or otherwise). This is definitely not the best idea.
3. Make a new format and print new duals for it
In the first place, the new duals could not mess up Standard or Extended (unless they killed Extended as a result of the new format, in which case the problem would be with Standard). While this might be a design challenge, it would not be too difficult of one. The real problem is that this option might feel a bit too forced. I understand that Wizards wants to push their new format if they launch it, but I would imagine that this is better accomplished from a marketing and advertisement perspective with reprints than with new cards. Compare the two advertising campaigns for M11:
"M11: Here's new cards that we hope will fit into our new format"
"M11: Here's old goodies that we remember fit well into a similar format"
With some tinkering, the latter would probably be a better strategy.
4. Make a new format and reprint the Ravnica duals
In my opinion, this is the best option. Ravnica duals probably won't warp Standard too much, and reprinting them would keep the price down. It would also encourage new players to enter the format, because they can get the mana base so easily in a core set (and many of them already have the Fetchlands from some former Legacy/Extended/Standard experience in the last few years). Reprinting Ravnica duals would also go hand-in-hand with reprinting some possible "new format" staples that Wizards could hypothesize would be relevant. Let's not get bogged down in the details of these cards and their balance for Standard, but it would be pretty cool to see stuff like Fires of Yavimaya, Parallax Wave, Pernicious Deed, Opposition, Cunning/Living/Burning Wish, Umezawa's Jitte (too risky probably), and Chrome Mox. Again, let's not worry about the individual cards. The point is, it would be really cool to see those bad boys reprinted. As to the effect on price, the Standard demand coupled with the new format demand should keep prices relatively stable, if not a bit higher than before.
These are just some options that I have considered, all of which Wizards could feasibly do. Of course, they could also do absolutely nothing, but this seems quite unsustainable.
I also must agree with quadibloc's idea of price drops. Once Extended rotates, a lot of cards will simply become unusable. These are cards that are good in Extended but just not good enough for Legacy. These price drops will probably happen with consistency every year that Extended experiences a rotation. A New Format would likely fix that.
-ktkenshinx-