In reply to Derry:
Inkeeping with all the reasons above, clearing out a race calendar has made people focus on other things, but it's also allowed a better, more consistent approach to training over a prolonged period of time. It's this 3-6 months of quality time on feet that has allowed a massive aerobic base to be formed with the required recovery to make use of this, which can then be put to use on these big jobbies. SO often we hop from race to race without recovering properly, gradually wearing the base down with constant taper-race-recovery cycles.
I also wouldn't be surprised if road/track/XC races over winter see big leap in performances from some as aerobic bases are sharpened in these communities.
Personally, I've been working early shifts so have had from ~2/3 each day to get out on the hills - much easier to fit in 90mins at 2 than at 6/7!
Obviously how Beth Pascall has managed this whilst working as a paediatric reg is another matter, but most medics I know who are outdoorsy seem to be quite good at getting good training in - probably a case of 'I have to go now so I will' and not sitting at home thinking about it like we can sometimes do!