The temporary item buffs (e.g. poisons, sharpening stones and shaman weapon buffs) introduced in Patch 1.11 will no longer persist through zoning or logging out.
“Players will notice in the latest PTR update that a change was made to the functionality of temporary item buffs (e.g. poisons, sharpening stones and shaman weapon buffs.) While we only just recently allowed the affects of these temporary item buffs to persist upon zoning and logging out, due to the extra demand it was placing on our hardware we’ve decided that for the time being, it was best to revert the change. We do anticipate this functionality will be available again once the anticipated hardware upgrades have been completed in preparation for the Burning Crusade’s release.
We thank you for your understanding.” – Nethaera
Well, I really enjoyed not having to put on poisons every zoning, but apparently Blizzards “excellent” Hardware cannot deal with it. If it was not that sad it would actually be funny.