Cheerful Dave - Very observant.
I did, of course, mean 12 weeks out to 4 weeks out. 
Theres certainly plenty quality posting already from people who have been there and done it so we should all pick up the odd idea as this develops over the next few weeks..
Keir - I was actually looking at the weeks that you labelled 12 down to 5. There are certainly plenty runs in the 14-20 mile range to back up the 20+ efforts but again I would put up for discussion the balance between the two.
This isnt to say that we are talking rights and wrongs in any of this, we are more tinkering around at the edges.
On a very basic level, training for a marathon is about running plenty miles and running some of them a bit quicker. Everything else is mere detail.
But then when we start adding detail, we can home in on this 8 week period as being the powerhouse/engine of the marathon prep. Everything before is just about getting strong enough to tackle the 8 weeks with enthusiasm and the 4 weeks after is getting ready for race day.
1. Yes, the 14-15 MLRs would be ideal for the progressive 10 milers. I always have 4 miles warm up anyway so it usually makes for a 14 mile session.
2. In week 4 (that is 4 weeks out from VLM day) you have scheduled:
Weds: 14 MLR
Sat: 21 miles with 14@PMP
Because this is 4 weeks out it is the ideal time to get an aerobic 26 miler in, something which has worked for both of us in the past and highly recommended by Charlie Spedding. The benefits seem to peak 2-3 weeks after and then gradually drift away so although running 26 miles so close to a marathon may seem risky, experience suggests otherwise. Of course, it needs to be gentle.
So, would it be feasible to turn the Weds run into the PMP session or a progressive 10 miler and then convert the Saturday run into an aerobic 26 miler?
It is only a suggestion because as mentioned above, BR ran a strong marathon off a longest run of 18.6 miles.
3. The intervals question is interesting because you could have a very successful marathon campaign without undertaking any interval sessions at all as long as you are regularly working the upper aerobic system. I didnt run any interval sessions at all in the lead up to Chester but still got my best HM for years bagged in the build up at 1:18:41. I did, however, race a lot and did plenty progressive stuff.
They seem like a default 'Go To' type session that gets included because, well, plans have interval sessions dont they? But is it better to kill two birds with one stone and build the hard efforts into longer runs/races and dispense with interval sessions altogether during this crucial 8 week period?
Now theres a question that will divide opinions..........
Edited: 24/12/2012 at 16:10