I have read one posting about a couple who had expired H-1 and no transit visa who were flying on delta, they were rerouted through london via british because the ticket agent at the port of exit(atlanta) would not let them fly through frankfurt with an expired visa. I know defjam on this board also had similar concerns and has done some research on this. From previous postings i have seen with an expired visa you can fly through london, amsterdam, milan, singapore, moscow. with expired visa transit visa must be obtained from zurich, frankfurt,paris for onward journey(usually the check is done at port of exit here, and if you have a ticket agent who is ignorant, you will get through). You can check the websites of these countries for any new changes also.
Hope this helps.