I use our conservatory as a playroom all DD toys are out there plus a settee, TV, Sky and DVD player. If its very cold and dont fancy putting the radiator on out there then she picks one or two baskets of toys to bring into front room and play and then we put them away and pick something different in the afternoon.
Would be lost without it as she wouldnt have ben able to have the big toys she loves (ie ELC Kitchem etc) as wouldnt want all of these in my front room and shes not really old enough to play in her room yet (shes 2.2) also in the summer its lovely as we have the double doors open to the garden so she gets to take her toys in and out of the garden. We thought about making the conservatory a dining room and using the dining room as the play room but it doesnt really work in our house but my advice to anone buying a house these days is if you think you may have kids try and find a house that you'll be able to use one room as a playroom/toy storage room. Like you when she gets older (and DD2 who is due in jan) I'll make it into their homework room/lounge den for when friends come round.