My earlier post (9th November) provides a list of the bug fixes, etc along with details of new camera and lens support. However, at least one significant bug appears to have slipped through the net.
Bug description – Lightroom can’t switch to Slideshow module. If you should experience this problem and have a second monitor connected to your computer then the monitor will need to be disconnected. A bit extreme, I agree, but it seems to be the only workaround at present.
Adobe have also released a Knowledge-base document that provides some useful information on maximising Lightroom performance. The document can be reached at Lightroom Performance Tips.