Hopefully you will be able to find a little peace within this one thread. As for me, I learned the hard way by worrying my self to death over it and searching for months on the internet!
Mine is an 08' that I bought new in 2010 with zero miles on it. From day one it had the idle surge. At around 4000 miles it stalled out when slowing down for a stop light when I pulled the clutch to downshift. It scared the crap out of me the fist few times it stalled because after the downshift and let out on the clutch on a motor turning @ ZERO rpm + rear wheel lock-up and slide!!
I took it to the dealer, complained and demanded they find the problem. They could not get it to replicate the problem so I just kept dealing with it. By the time it was @ 5000 miles, I never saw the stalling problem again.
By the 10000 mile mark, the idle surge calmed down to only being a problem in hot weather and only does it every so often. Not every stop like it use to.
I tried the "ECM Reset" thing several times only to find it surging again a hundred miles later. I had it in the shop and had it looked at and there was no acknowledgement of a wide spread problem. But we all know it is wide spread.
So in hind sight I have to question if it was really a problem or not. And since my 08' Runs great and buts a smile on my face every day, I have to say it is not a problem but simply the nature of the engine in the GL1800.
Some don't do it at all, some do it sometimes and some do it a lot. But in the end, they all run the same and are all great motors.
Enjoy your bike and do not let the idle surge bother you, it will calm down over time.