To address some of the comments in the thread:
1) Catalyst the Protector is an incredible early-game item. It will keep you in the lane and in the fight with the instant mana regen and heal upon leveling. I underestimated it before, then someone in the other major Nasus thread recommended it over the Chalice I was using. I tried it, and fell in love. Chalice is certainly a viable option instead. I personally prefer Catalyst, especially because I can quickly turn it into a Banshee's at level 18 without losing any benefit instead of selling it as you would a Chalice late game. I find that I'm able to spam SF just fine with Sapphire Crystal until I have enough money for the Catalyst.
2) Stark's is an incredible item, but NOT for Nasus. I get it every single time on every melee dps I play, except him. The armor pen is great, but he has no use for the regen, and he wants attack damage and crit much more than attack speed. For Nasus, Trinity Force and Infinity Edge are so good (because of how they synergize with SS) that you need to rush those before buying something like LW or Stark's. Those are great items for physical damage, but just aren't good fits for Nasus.
3) You can no longer stack Brutalizers, sadly. Though it's a great item for him, I personally prefer the 20% cooldown reduction for a similar price from Glacial Shroud. To become an offensive powerhouse, you just need TF and IE. After that, get a Glacial Shroud then make some defensive items (Banshee's, Frozen Heart, and Guardian Angel are my preferred picks here, especailly since I already have some of the components).
I'm still using my build from the second post of this thread, and still loving it.