Hm... We have sources of GWT from repository, however we just look on them (for example on GWTShell) and don't build GWT user library. So, I can not test with trunk GWT.
Can you build gwt-user.jar and send to support, so we will look on it and decide how to support?
1. Yes, I saw discussion in GWT development forum.
2. We will find some solution.
May be this will mean that GWT Designer 1.6 (may be different version) will support only GWT 1.4.
3. No, 1.5.1 is development version, but we support only releases of GWT.