There are other goodies in 1.18.1 missing from the current readme. We'll update the readme file retroactively next release. We'll also post a full description of some of the new features. For today, feel free to download and play with 1.18 for sport, but save the heavy duty "what is" and "how do I" questions until we get a chance to catch up.
1.18 is a development "bleeding-edge" release branch. Its been a long time since we've had development releases, so its worth a short recap on what that means. 1.17 remains the stable release branch. We will continue to fix all bugs found in 1.17, and then forward port them to 1.18.
No guarantees are made regarding the stability of 1.18. It may report incorrect results. It might cause your computer to catch fire. Customers should not upgrade to 1.18 unless they have no choice. At this point, I think Sacramento is the only account that fits this description. Once 1.18 has been tested and declared stable, you can upgrade customers to get the goodies, like saving report settings. Until then, be afraid. Be very afraid.
Finally, remember that upgrading a database to 1.18 is a one way trip. Make sure you backup your database before you upgrade. There might even be some problems with the upgrade function itself. It there is, it will probably mean a re-upgrade from 1.17 to fix the problem. Its unlikely, but hey anything is possible on a development release.
And finally, have fun!