Singapore Airlines is a premium carrier that that is known for conisitently maintaing a young fleet, the take away is not that Singapore was getting rid of 10yo planes but that they did not buy more as replacements.
The problem is that just about every airline sophisticated to operate an A380 has either bought (at least) as many as they need (Qantas, Air France, etc.) or made a strategic decision that the A380 is not the plane for them (Cathay, the US big 3, etc.). There's a rumor that BA might pick of a few of the used frames, but that's it - and they only have (IIRC) 6, so it's not like that will make much of a dent in the market even if they double their fleet size.