gmail and the conversation ui
Here's something to watch on Gmail. When the masses come streaming in with visions of 1gb of storage, will they "get" the display of messages by conversation? Or will Google need to add a "traditional" list view where each individual message is iterated? I'm still getting used to the Gmail approach; the expanding / collapsing message cards are useful (they put individual messages in contest, and they help you catch up on new mailing list traffic quickly), but collapsing all the messages of a thread into a single item in the "all mail" view isn't entirely intuitive at first.
(And of course, I'm imagining Google leveraging this UI into Groups and potentially the RSS aggregation space. Groups makes sense -- conversations can be expanded / collapsed like email. RSS aggregation would be intriguing; they could combine conversation threads across feeds based on content analysis. "Here are all the posts in chron order from the feeds you subscribe to about Janet Jackson's impersonation of Condi Rice.")