* byobu - nicer than plain screen with good defaults, for example key binding for scrolling is like in a regular terminal.
* sbuild - nicer than pbuilder, defaults to overlay directory instead of tarball, hence fast by default, nice colors, build summary. I have heard about it for a long time, but the recent mention during Ubuntu devel week made me curious. It is friendlier now - no need for LVM snapshots. http://wiki.debian.org/mk-sbuild
* syncpackage - which now allows syncing from Debian if you have Ubuntu upload rights. No need to burden the archive team members anymore for every sync or go the roundabout way of getting from Debian and then uploading manually without changes.
* Modern Debian packaging in the form of the 3.0(quilt) source format and the new dh tools. The former allows a cleaner separation between the upstream and distro bits while the latter makes the debian/rules file much shorter and cleaner even than with CDBS, let alone with the classic debhelper way.