No perfect answer but maybe it can push you in the right direction.

create table #tbl (name varchar(128), s bigint)

declare @db varchar(128)

declare @sql varchar(2048)

select @db = ''

while exists (select Name from master..sysdatabases where name > @db)

begin

select top 1 @db = Name from master..sysdatabases where name > @db order by Name

select @sql = 'insert into #tbl (Name, s) select ''' + @db + ''', sum(size) from ' + @db + '..Sysfiles'

exec(@sql)

end

select * from #tbl

drop table #tbl

/T