Whatever claims you might make about Google Wave and its potential, ease of use would not be high on the list right now. Wave becomes much more straightforward once you start incorporating extensions for common tasks, and a forthcoming extension gallery will make those a lot easier to find and add.
During a mini-conference on Wave at Linux.conf.au 2010 in Wellington, Google showed off its forthcoming Extension Gallery for Wave. While you can currently browse through a basic list of extensions and add them manually, incorporating an Extensions gallery link into Wave itself (which is already active on a small number of test accounts) is much simpler. The same approach certainly proved helpful with Chrome's Extensions feature.
Initially, the list will feature a dozen extensions hand-picked by the Google team, including video chat, mind mapping and highlighting, along with extensions such as trip planning and ordering takeaway food which we suspect might not have global relevance. Eventually, the gallery will also incorporate a user rating and review system, but even the basic system will be a welcome improvement when it becomes more widely available later this year.