A Beechcraft A35 broke out on an instrument approach to an uncontrolled airport to find an aircraft 1/2 mile ahead of him making a VFR approach.

Narrative

I was on approach (GPS LNAV/VNAV); in IMC. ASOS reported ceiling 800 FT. Approach called '2000 FT till established; cleared for the GPS Runway XX approach ZZZ.' At about 1800 FT Approach called 'radar service terminated; cancel on the ground or in the air.' I was IMC at the time and did not switch to UNICOM. I continued on the approach and broke out of the clouds at -900 FT (DA 570 FT) and immediately canceled IFR and switched to UNICOM. At the next moment; I both observed and was alerted (on UNICOM) to a twin (ABC Airlines) on short final; about 0.5 miles ahead of me. I slowed as much as possible and chose to land; a moment after the other plane cleared the runway. When I entered the FBO; I asked how that 'airline' had arrived VFR in such poor weather (they were not on ATC frequency during my approach) and was told that they 'have a special VFR waiver and always operate; even in much lower weather' and I 'should have been monitoring UNICOM during my approach.' I contacted ABC Airlines and asked about their procedures and was told that they 'routinely fly VFR with 500 FT ceilings and will go down to 300 FT ceiling with 2 mile visibility.' I asked if they monitor Approach and was told; 'some of the pilots do.' Considerations: I should have switched to and reported to and monitored UNICOM as soon as I was 'radar service terminated.' I never expected there to be VFR traffic in the weather in this airspace. Shouldn't an aircraft on an SVFR clearance be in contact with ATC?