I just started my upgrades to Lucid for my 3 boxes and started with my XBMC box which is an Acer Aspire Revo. I hit a few snags so I figured I'd start a thread for a one stop shop for current XBMC issues with Lucid since a number of people seem to be having them. First, lets start with install.
The old PPA for XBMC does not have a Lucid version of XBMC. To install it, run:
That will allow install of XBMC.
sudo add-apt-repository ppa:team-xbmc-svn/ppa
The next issue I had was video. The Revo has an ION nVidia card which should have VDPAU acceleration but all of my video was choppy. In order to get VDPAU, you'll need to install libvdpau1.
Video should fly now. Finally, audio over HDMI. I currently have the HDMI going into a television, so standard audio is fine. Under System -> Preferences -> Sound and the Hardware tab, I had to change Profile to Digital Stereo (HDMI) Output + Analog Stereo Input. This gave me the menu sounds in XBMC as well as movie audio. If you intend to do passthrough, you'll need to go into XBMC and switch from Analog to Digital audio and HDMI output. This consistently failed for me. On the XBMC forums a solution was to add your user to the audio group. This didn't work for me but just a tip in case it does for you.
sudo apt-get install libvdpau1
Finally, the movie scraper doesn't seem to be working ATM for images. (Now working)