If you read the patch notes Xür, when he appears, is now going to sell exotic shards for 7 strange coins. But the question is, what will they replace? Will they be curios and replace a weapon telemetry or sparrow drive? Or will they be exotics, being that it is after all an exotic shard and replace, most likely, the exotic engram. Clearly an intellegent choice given that public events now award motes of light rather than ascendent materials. No it won't be just added as a new item. Bungie has already shown they hate duel-existence.