Just a little chunk of information as the wider frame of things has already been discussed quite extensively, for example here .
For background reading, just follow the links provided on the Greatest Auk's site, especially this one, which provides even more links to follow and so it goes on and on until the power company disconnects your electricity as you have forgotten to pay your bills over following all the links and then you die of hypothermia.
I know this was awefully off-topic, but on the other hand I found it so outrageous I just had to mention it sometime somewhere.
Aaanyway, back to birds and windows.
The Swiss Ornithological Research Institute Sempach (sort of the Cape May of Switzerland, only that in technical terms Switzerland doesn't have a sea next to it) in conjunction with Birdlife Switzerland has published a guideline for builders, architects and the interested public (whoever might be interested) on how to avoid window strikes by birds.
You can find the site here and the pdf version here. If you feel adventurous, you can also read the German, Italian or French version (click on the flags in the upper right corner).
They do not mention the Sibley approach though, and Sibley also apparently hasn't done any further research into the matter.
Does anyone out there have additional information they'd like to share with me?
The whole topic really is a pressing issue and sadly for this Coop, New Jersey isn't (future) Switzerland. Let us just hope initiatives like the one in Switzerland will be received favourably by the general (building, planning etc.) public there and elsewhere so that window strikes stop to seriously mess up our joy of spotting good birds at unexpected places.