Exchange Server 2007
As the Outlook Web Access feature of Exchange Server 2003 is not a beauty when a non IE browser is used, I hoped this might change with the new Exchange Server 2007.
However I now tried a hosted demo of Exchange Server 2007 (free signup is possible) and I am rather disappointed: Although the frontend now looks much better and clearer, it still does not use AJAX technology. A monthly calendar view is also still missing. Even worse is the fact, that the weekly calendar view has been removed and now only the daily view is available. Thus you cannot get an overview of your schedule anymore.
Microsoft seems to have not noticed that cross-browser AJAX is possible today and should be used by webapplications. Other examples show that this is not just a dream but really possible.