Yes, it's May, and the exact failure is "Light source and lamp not compatible".
The accompanying guidance states: "Some vehicles may be fitted with High Intensity Discharge (HID) headlamps. It is not permitted to convert existing halogen headlamp units for use with HID bulbs. If it is clear that such a conversion has been carried out, rather than replacing the entire unit with one designed and approved for use with HID bulbs, the headlamp should be rejected".
Personally, and famous last words here, I think we would probably get away with it.. I agree with Tareim above - I think with the projector lenses we won't fall foul of "light source and lamp not compatible". I also hold the (slightly risky) assumption that, to the majority of MOT testers, it may not be "clear that such a conversion has been carried out.."
Fingers crossed anyway!