Transactions in export
Create view and routine options
Variables editation, especially timezone
Accept Tab in SQL textareas, Ctrl+Enter to send form
Highlight SQL textarea, then display query inside textarea in select - may use external CodePress
Blob download and image display in edit form (important for Editor with hidden fields in select)
Add title to Logout, edit (in select) and select (in menu) in style "hever"
Shift-click in checkboxes to select range
Export by GET parameters
Only first part of big BZ2 export is readable, files are missing in TAR
Auto-refresh processlist (thanks to Jan Garaj)
Show pagination above and under the table in select
? Filter by value in row under <thead> in select
? Column and table names auto-completition in SQL textarea
? Aliasing of built-in functions can save 7 KB, function minification can save 7 KB, substitution of repetitive $a["a"] can save 4 KB, substitution of $_GET and friends can save 2 KB, aliasing of $connection->query, $connection->result and $connection->quote can save ~ 3 KB, JS packer can save 1 KB, not enclosing HTML attribute values can save 1.2 KB, replacing \\n by \n can save .3 KB
? Branch binary_compile: LZW compression of translations can save 30 KB, LZW compression of all texts can save 11 KB, remove of base64_decode() + using chars 127-255 in minification can save 1 KB

Editor:
JavaScript data validation - columns containing word email, url, ...
Joining tables - PRIMARY KEY (table, joining)
Rank, Tree structure
Add whisperer to fields with foreign key to big table

MySQL:
Saving of MySQL 5 BIT data type - don't use quote()
? Geometry support

SQLite:
ASC and DESC instead of text length in index
Delimiter in export and SQL command
Backward keys in Editor

PostgreSQL:
user types
Users - SELECT * FROM pg_user
ORDER BY COUNT(*)
Export - http://www.postgresql.org/docs/8.4/static/functions-info.html
Column rights - http://www.postgresql.org/docs/8.4/static/functions-info.html
Dollar terminated string in SQL command
bool in Editor

MS SQL:
Non UTF-8 character sets
Rename by sp_rename
Detection of table collation
PDO driver with seek

Oracle:
clob comparable with string