You know, with the new tenacity stuff, I think Irelia's actually got MORE tenacity in S3. And now she doesn't even have to buy Merc Treads to do it! (admittedly, the other tenacity items aren't screaming "OH, PLEASE, TAKE ME NOW!")

Also: Elise's Miracle might be worth the 1.1k gold you spend on it, if you grab it early enough, since it stops taking up an item slot.

I grabbed it in a bot game as Skarner, and while it wasn't "ZOMG, FANTASTIC!" I ended up having a LOT of passive regen, enough so that I could vanish into the enemy jungle at fairly low, clear their wraiths and golems, and walk back out with ~3/4 of my HP. Mana was a different story, but yeah.