Is it possible to configure a SharePoint 2010 list to the default form for editing and viewing while displaying my custom InfoPath form only for new items?
In order to use mixed, i.e. both Infopath and default Sharepoint form templates, after creating Infopath form for and publishing to a list, you should remove association with Infopath form template and only then to choose again a specific as[x web part page...
Navigate to list > on ribbon List tab (under List Tools) > Settings > List settings > Form Settings > choose radiobutton "Use default Sharepoint form from the server" without checking "Delete the Infopath form from the server" > OK
Only then, in Sharepoint Designer 2010 Lists and Libraries > choose a List > in section Forms choose
and press on ribbon "Set as default"
Now, Infopath form web part page (linked eventually to infopath template) is used for new (aka create aka add) a list item while default sharepoint web parts (using default sharepoint lisr template) page for View and and Edit.
And you should repeat all the steps after each (quick) publish from Infopath Designer. No other choice, O am afraid...
Actually I posted in msdn forum about this user-unfriendliness: