Even doing the swap, the fit is ok. But you will have a problem with the ri ght headlamp with the power stering reservoir mostly it will hit because of the heamlamp internals. Also the wiring for the lamps will be a problem also, because you have to wire for the low beam to stay on when you change to high beam.
I find it interesting that for the most part, people want to 'upgrade' to the 2012 headlights and taillights when I actually like the originals as well or better - especially the taillights. I bought a 2012 for the mechanical upgrades rather than the cosmetic changes. First and foremost was the 6 speed automatic.
Even driving my dad 2012 soul base. It feels quite different. But I don't like the 6 speed transmission. Its feels like Jeremy Clarkson driving the semi trucks. It changes gear like crazy! The ECO system is great for city driving but not great for mountain driving. I will stick for my 4 gear auto because of the longer range between gears.
on-topic: you can try to change the 12 headlights to pre-11 ones, but be prepare to do heavy modifications to the wiring. I would recommend you stay with the 12 headlights.
I'm going to get a 2011 headlight from a local supplier and try. I can't see them retooling for a headlight change. I'm good with the supplier so If it works I can return it and will be happy to trade. (all day long). Don't see me installing them with zip ties though.