resharper-api

Information about upgrading a Resharper plugin to v 5.0

I like the sound of the Exceptional plugin for resharper, but it says it currently only works with v4.5. Does anyone know what is involved with upgrading to 5.0 and how much things have changed, which bits will need to be looked at etc. I am quite tempted to upgrade it but would like some pointers before I start... ...