Just returned from the Thakhek Loop (as usual I changed my itinerary straight away, and it was worthwhile - a report will follow when after my return home in a couple of weeks...), and when I spend some time in Kong Lor Village for the Kong Lor Cave I was advised that there is now a direct bus between Vientiane and Kong Lor. There were quite a few tourists who were not aware of it, and left the bis to Pakse at one point, and took a songthraw afterwards. So I thought it would be good to post it here to let others know.
I only know that the bus leaves Kong Lor at 6.40 in the morning for Vientiane, but do not know the departure time from Vientiane, or what the price is.
This will make the cave and village most likely a more easily reached place for tourists now.
PS: I have a great time again in Laos right now....