I've just noticed that a page about this forthcoming publication has appeared on the IEE Web site:
Although the full title suggests that it's mainly concerned with Part P, there's an article in the Autumn 2004 edition of 'Wiring Matters' that refers to "a good understanding of those other requirements of the Building Regulations that impact upon electrical installations." Parts E and L are mentioned in the context of cables and thermal insulation:
"Cables may today unavoidably be totally covered in insulation for part of their length. The new [guide] includes some simple standardised circuits including for cables totally enclosed in thermal insulation for part of their length. The design requires the use of the new white coloured Low Smoke Twin Flat and CPC (6242B, thermosetting 90 deg. C, BS
7211) cables."
"Another feature of the new guide is its particular user friendliness." (That I'll believe when I see it.)