A lot of people are asking me when gcc-4.0 is going to go into ~arch. The answer: soon :) I want to get it in as soon as possible, but I also want to make sure it is not going to break on common packages. If you want to help out, go check out the gcc4 tracker bug. If something doesn't have a patch yet, it would help if you tried to find one or came up with one that we could use.