I completed the consultation document (linked to in previous post) and commented about the requirement for 8.33KHz radios only being needed for 9 months. A pro-active chap from NATS spoke to the CAA and came back to me with the following information.
We have been in discussion with the CAA regarding the 8.33Khz radio carriage issue. They have assured us that an exemption for SVFR aircraft within the London CTR will be issued to cover the period between 1st January 2014 and the reclassification of the London CTR to Class D. You should see a NOTAM covering this exemption shortly.
Well done NATS for clearing this up.