I do all of my audio work in Audition. I don't really care for Premiere's audio facilities. With 2.0, they do integrate together. From a PPro timeline you can right-click on a clip and select 'edit in Audition', do your sweetin' in Audition, and save the results which are then automatically loaded back in the timeline. It's not perfect integration but it's getting better.
I'm a big fan of Audition. There's not too much you can't do with it audio-wise. It's biggest deficiency is that it does not integrate well with the pro audio world (i.e. Protools). Adobe is actually in the process of replacing Audition in it's video production suite. They just announced a beta release of 'Soundbooth' which will be a new audio tool for those who are not really into audio. According to Adobe, Audition will continue as a standalone tool for more hard-core audio uses.
yes, Edit in Audition. it works as an extension of Premiere and the integration is damn near perfect. I was really impressed when I tried it the first time. Adobe has finally figured out how to make programs integrated in a way that works and it makes the editing process so much easier. Just see what happens when you dump unrendered AE compositions into the Premiere timeline and you'll understand how far ahead they are.