With all due respect, WoTC will just print another set of lands. Why not just print these:
New Taiga
Land
Tap: Add R or G to your mana pool
No duals, no helping your Nightmare or retrievable with something like a Tithe, but still great lands for doing what you need done. Or you could print these.
Cold Taiga
Snow Land - Forest Mountain
You could even do this
Legendary Taiga
Legendary Land - Forest Mountain
for just one copy in play at a table.
