Some good changes are coming to PHP6, it seems (for those who still care about PHP). A selection: register_globals will be gone. magic_quotes will also disappear. $HTTP_*_VARS has been removed, in favour for $_GET, $_POST, etc. E_STRICT error messages are included in E_ALL errors. Better Unicode Support. safe_mode is being removed. Thank you PHP people.
Pro: How FriendFeed uses MySQL (hint: as a hashtable with indexes) The database behind Plurk (twitter clone), also a hashtable Con: Databases as a service, they no likie hashtables