I's true, I just came back on March 2011, from LPB.There are too many trashes. I also went to Vietnam, from Saigon , Hue, Hoi An, Halong Bay, Hanoi and Siem Riep ( Cambodia). Hoi An is also the world Heritage,as Laung Prabang. It is beautiful.
I also saw more back packer tourist in Vietnam. Not sure what will be happending to Laos tourist industry in the future.