Pavey and Hayley both selected for the long course after 1st and 3rd finishes at Euro XC, don't know whether Pavey will run it though as she has expressed interest in the Euro indoors in Madrid. Hayley sure to run the long race but Radcliffe not yet decided as far as I know, but has expressed an interest and used the world XC as preparation for London in previous years. My guess is she will run if she thinks she is in shape to win it.
Liz Yellings record at the world XC is 13th 8km (2004), 19th 4km (2003), 18th 8km (2002), 17th 8km (2001). Other than '97, she has ran every year since '96.
Kathy Butler also wants to run (12th last year), so potential for 5 UK ladies to finish in the top 20. It would surely not be possible though to pre-select 5 athletes for a team of 6 (I'm not suggesting Butler will not run the trial, but if I'm calling for Liz Yelling to be pre-selected on her world XC record, Butler must also be considered).
For the men, Keska has been preselected for the men's long course after his 7th place finish at the Euro XC. No word on Brown's intentions, although he is also down to run London marathon, and the world XC seems to be a favoured 'warm up'