Recently some of us (who still care about DCI events

) went to the prerelease of Darksteel. As T1 players we were probably checking the new releases to find one or two T1 playable cards. While Mirrodin might have provided a little needed brokeness (Chalice, maybe Chrome Mox), Darksteel introduces a broken mechanic I hope will not appear in any other edition.

The Indestructible mechanic
When I saw the first indestructible cards I thought "No big deal, just some creatures and stuff for kids to be happy". Then I saw this card:
Darksteel Forge
artifact rare cost 9
Artifacts you control are indestructible.
This card will certainly help some Mud players and might put tinker like decks back in the game. It seems very broken to me. Other interesting cards are:
Leeches Tomb
artifact rare cost 4
You don't lose the game for having 0 or less life. Whenever you lose life, sacrifice a permanent for each one life you lost.
Blinkmoth Nexus
land rare
(basicly a 1/1 mishra's factory with flying)
Panoptic Mirror
artifact rare cost 5
Imprint- X tap: You may remove an instant or sorcery card with converted mana cost X in your hand from the game.
At the beginning of your upkeep, you may copy an imprinted instant or sorcery card and play the copy without paying its mana cost
(note this is an expensive card and might not see any use because of it)
Kraken's Eye, Last Word and Darksteel Collusses migth also have limited uses.
Will any of these cards make it to T1? Does anyone else think the indestructible mechanic is... well... "stupid"? Are there any other Darksteel cards worthy of T1 consideration?