Entirely new menu system Partially available
Major Form API improvements Partially available
New Schema API Available
New format for hook_install() Available
New format for hook_uninstall() Available
New format for hook_update_N() Available
The arguments to url() and l() have changed Partially available
Variable names can now be 128 characters long Not needed
Taxonomy terms are now associated with node revisions, not just nodes Available
format_plural() accepts replacements Notification only
New drupal_alter() function for developers Not needed
New module_load_include() and module_load_all_includes() functions for developers Available
hook_form_alter() parameters have changed Available
hook_link_alter() parameters have changed Available
hook_profile_alter() parameters have changed Available
hook_mail_alter() parameters have changed Available
$locale became $language Notification only
New hook_theme() registry Available
template_preprocess_* with .tpl.php files Not available
node/add is now menu generated Notification only
New watchdog hook, logging and alerts Notification only
Parameters of watchdog() changed Available
new hook_update_N naming convention Not needed
New syntax for .info files Available
Core compatibility now specified in .info files Available
PHP compatibility now specified in .info files Notification only
New db_column_exists() method Not needed
cache_set parameter order has changed Available
Cache set and get automatically (un)serialize complex data types Available
node_revision_list() now returns keyed array Notification only
New operation in image.inc: image_scale_and_crop() Not needed
New user_mail_tokens() method Notification only
New ip_address() function when working behind proxies Available
{files} table changed Notification only
file_check_upload() merged into file_save_upload() Available
{file_revisions} table is now {upload} Available
drupal_add_css() supports automatic RTL CSS discovery Not needed
Node previews and adding form fields to the node form Notification only
JavaScript behaviors: new approach to attaching behaviors Not available
JavaScript themeing Not available
Translation of JavaScript files Not available
JavaScript aggregation Not available
custom_url_rewrite() replaced Available
hook_user('view'), hook_profile_alter() and profile theming Notification only
Distributed Authentication changes Not available
hook_help() parameters are changed Available
Change Submit" to "Save" on buttons" Notification only
node_feed() parameters changed Manual intervention
hook_nodeapi('submit') has been replaced by op='presave' Manual intervention
taxonomy_get_vocabulary() changed to taxonomy_vocabulary_load() Available
hook_init() is split up into hook_init() and hook_boot() Available
Remove db_num_rows() method Manual intervention
Remove $row argument from db_result() method Manual intervention
Block-level caching Not available
Batch operations: progress bar for heavy computations Not needed
Node access modules: simplified hook_enable / hook_disable / hook_node_access_records Manual intervention
node_access_rebuild($batch_mode = TRUE) / node_access_needs_rebuild() Notification only
Upgraded to jQuery 1.2.3 Not available
Removed several functions from drupal.js Not available
The book module has been rewritten to use the new menu system Manual intervention
new helper function: db_placeholders() Not needed
Comment settings are now per node type Available
Check node access before emailing content Notification only
form property #DANGEROUS_SKIP_CHECK removed Available
'Access control' renamed to 'permissions' Available
locale_refresh_cache() has been removed Available
FormAPI image buttons are now supported Notification only
db_next_id() is gone and replaced as db_last_insert_id() Notification only
admin/logs renamed to admin/reports Available
New helper function: drupal_match_path() Not needed
drupal_mail() parameters have changed Available
New hook: hook_mail Notification only
Use drupal_set_breadcrumb() instead of menu_set_location() to set custom breadcrumbs Notification only
user_authenticate() changed parameters Available
Automatically add Drupal.settings.basePath Notification only
Get an object relevant on specific paths Not available
hook_access() added parameter Available
Can't add javascript to header in hook_footer() Available
Translations are looked for in ./translations Available
hook_submit() has been removed Manual intervention