you could query sys.assemblies;
i'm sticking the results in a global temp table for ease of reporting, for example:
CREATE TABLE [dbo].[##RESULTS] (
[DBNAME] NVARCHAR(128) NULL,
[ASSEMBLYNAME] SYSNAME NOT NULL,
[ASSEMBLYVERSION] NVARCHAR(4000) NULL)
EXECUTE sp_msForEachdb 'INSERT INTO ##RESULTS select ''?'' As dbName,name As AssemblyName,clr_name as AssemblyVersion from [?].sys.assemblies '
SELECT * FROM [##RESULTS]
ORDER BY [ASSEMBLYNAME],[ASSEMBLYVERSION],[DBNAME]
Lowell