"Will it really trickle into the economy or just repair balance sheets?"

I think that that is exactly why the socalled growth pact that Hollande wants could become interesting. When you use QE not just to defend balance sheets of banks that are not going to lend anyway, but use the QE for huge infrastructural and or innovation projects, you have a better chance to get that money into circulation. Would be nice if the would do the same in the US.