I posted some ideas on how to improve the situation with inexperienced mappers using potlach. If got many comments on that one so I can see others thought about that, too. And I'm really happy that almost all of these were productive comments. It might be worth reading them (http://www.openstreetmap.org/user/egore911/diary/3177) but I'll summarize a few them here for you.
* It seems potlachs undo/redo feature isn't the best right now. Please help the authors fixing these by pointing out what exactly is wrong with it. Having a good undo/redo is really necessary for a clean workflow.
* Potlach will gain support for "highlighting" bridges. This is really good to know and I really look forward to it.
* One can't compare JOSM with Potlach. Some people try to say this one is slower or that one has more features, this one is more intuitive, etc. One should use whatever he is confident with. I use JOSM because I'm a Java developer myself and if something is not working with JOSM I can implement it (i.e. I added importing NMEA files to JOSM and wrote a patch to configure the proxy using the GUI). I also like the "stand alone application" more than the "web client" approach. But that's personal taste.
* Some people suggested guiding people to learn how to map. This might be a possible solution but I think it's a hard one. I think the "average user" will have a learning curve like the following:
1.) Look at the map and see that some streets in his neighbourhood are missing
2.) Starting potlach
3.) Clicking around in potlach to add the street to his best knowledge
4.) Finding more streets missing
5.) Adding more streets and looking at existing streets to gain knowledge about them.
6.) Adding more streets ...
I think starting with mapping isn't hard but error-prone.
* It seems for the crossing/link there are no yahoo aerial images available. I still wonder what method was used to add the incorrect information than.
Right now my region is in really good shape and thanks to other users working in this area (especially astersteiner) we are making really good progress. And also thanks to the potlach users who added all these railways!