A new version of Nginx is out, 1.4.5 from the stable tree. According to Nginx.org website, this is the changelog with the most important changes in this version, as you see all the changes are related to bug fixes, no new features or improvements were made on this version:
*) Bugfix: the $ssl_session_id variable contained full session
serialized instead of just a session id.
Thanks to Ivan Ristić.
*) Bugfix: client connections might be immediately closed if deferred
accept was used; the bug had appeared in 1.3.15.
*) Bugfix: alerts “zero size buf in output” might appear in logs while
proxying; the bug had appeared in 1.3.9.
*) Bugfix: a segmentation fault might occur in a worker process if the
ngx_http_spdy_module was used.
*) Bugfix: proxied WebSocket connections might hang right after
handshake if the select, poll, or /dev/poll methods were used.
*) Bugfix: a timeout might occur while reading client request body in an
SSL connection using chunked transfer encoding.
*) Bugfix: memory leak in nginx/Windows.
You can get the latest stable version from Nginx.org download page.