I have begun to receive bug reports. The most common one is that Explorer may hang at launch at the point where plug-ins load. My guess is that this is a reincarnation of a problem (described here previously) with earlier versions of Explorer. The solution was to delete Internet Config and Explorer preferences files.
Toronney Mixon writes that he was unable to download mail using Microsoft Internet Mail and News and that Microsoft Help replicated the problem (still, I suspect many users are not having this symptom).