For me, with today's winetricks from svn and wine from git, winetricks dotnet30 seems to work well. It appears to hang at the end because of http://bugs.winehq.org/show_bug.cgi?id=25059 but that's cosmetic; if you look for the icon hiding on the taskbar, you'll see the installer completed.
Don't know if the resulting package works, but at least it installed for me just now once. Ship it! :-)