I don't think the Terras will compete with the ZRS really, especially not the 32mm model. The ZRS price point is ~$200, whereas the Terra ED is going to be $349 for the 8x42 and $399 for the 10x42. A difference of $100-200 isn't a big deal in alpha land, but in the budget category those are two different subsets of buyers.
I do think the Terra ED is going to be a major player, but the major threat is to the old $300 standards for budget buyers -- the Nikon Monarch and the Eagle Optics Ranger. I know that when I bought my old 8x42 Rangers 7-8 years ago for $300, I would have had to think twice had I been able to get a quality Zeiss for 50 bucks more. Compared to the Monarch 5 and Ranger, the Zeiss offers a wider FOV and that elusive Zeiss cachet, and almost certainly better resale value as a consequence. If there are not major QC issues with the Terras I think they are going to take a big bite out of that $300-400 market, not because they are necessarily that much better than the other options optically, but because of that blue badge.
Secondarily, there will be a threat to the China ED models in the $300-400 range (Zen ED2/3, Vanguard Endeavor ED, etc) but I think there is a slightly different market there than the more popular options like the Monarch.
