I spent a merry lunchtime looking at the new CTP of Phone 7. It is looking very promising, but interestingly it doesn’t (yet?) include options in the UI to strong-name your library projects. It does, however, still seem to work if you just edit the csproj by hand.
Notepad will do the job, or in Visual Studio right-click in Solution Explorer to “Unload Project”, then right-click again to “Edit …” it.
Add the lines below, and finally right-click to “Reload Project”. Inelegant, but I can live with it ;-p
I have no idea if this is a sane thing to do, but it makes my code work (I’m doing something a bit out of the ordinary), so I’m happy.