There are a few more possible money sinks that haven't been mentioned here... the main ones I can think of without putting to much thought into it are:
* Crafting (both recipes and materials) (though not really a 'sink' as it produces stuff)
* Consumables (especially important once PVP comes out - surely there are going to be items all PVP lvl60's will want to give them an edge, e.g. potions etc.)
* Is there any upkeep in D3? (either weapon repairs, follower upkeep etc.) - what about dye's etc. if you change armour appearance?
I'm sure there will be a few others too.