New Radio Hitch-Hiker's

BBC Cult Site:

A six-part adaptation of Life, the Universe and Everything will be up first in the spring. This will be followed towards the end of 2004 by an eight-week serialisation combining So Long and Thanks for All the Fish with Mostly Harmless.
[...]
The Hitchhiker's production is set to re-unite six members of the original cast: Simon Jones, Geoffrey McGivern, Mark Wing-Davey, Susan Sheridan, Stephen Moore and announcer John Marsh. Those joining them will include William Franklyn as the voice of the Book and Richard Griffiths as Slartibartfast. The late Douglas Adams himself will appear as Agrajag (a cameo he favoured playing) thanks to recordings made for Dove Audio's unabridged book readings.

Substantial amounts of original cast. This could actually be quite good.

(Via the RSFG mailing list)