As ABC newspaper says today, Iberia will start in Jan 06 operations of its LCC from BCN (which probably will be called Mediterranea).
They will operate from BCN (as hub) to compete with Ryanair and Vueling.
They will use the money of their shares in Amadeus. Other possibility will be to buy part of an existing carrier. They say Vueling, that operates from BCN.
Buying part of an existing carrier is something they are really considering, because will be much more easy to keep the costs low, as wouldn't be Iberia the only owner.
Link (in Spanish):