The website for the conference is now up:
The Centre for Geospatial Science of University of Nottingham, Open Source Geospatial Foundation (UK Chapter), ICA Working Group on Open Source Geospatial Technologies, SOSoRNET and Open Knowledge Foundation are organizing the First Open Source GIS UK Conference on 22nd June (Monday), 2009 at the University of Nottingham.
http://www.opensourcegis.org.uk/ for more information.
I am on the committee through my work on open data but likely unable to attend the actual event as it conflicts with a conference I’ve committed to in the US. Looking forward to participating though and seeing the submissions.