Hi I'm new to arch but I've got automatic sig checks by pacman running fine so far on stable with just pacman4 from testing set to Optional (for the databases) TrustedOnly. I just had to tsign Ionuts master key with mine manually and also Allan Mcraes which seems to be unsigned by the Arch Linux Master keys oh and now also Ronald van Harens. I haven't tried many packages but when tryinh abs which is unsigned it went fine but the signed rsync threw angel velasquez angvp@archlinux.org is unknown trust. It appears to be signed by Pierre's Master key which I have lsigned with no luck. Not sure if you find these reports useful or just annoying until launch so let me know for any others I find. Looks like a good highly adaptable system :-)