as of right now my mileage is on the low side because i just recently came off of a marathon (boston) but i never had a problem with the mileage during the training for that one. for this 2nd marathon (nyc), i'm looking to better on the time and from what i read the 800 repeats seemed the way to go.
my schedule is as follows:
monday: weights (squats, leg press, calves, d1/d2s, hammy curls and misc upper body stuff) and cross training
tuesday: 800 repeats (starting at 4 repeats and working up to 14 repeats)
wednesday: easy run of 3-5 miles
thursday: 7-9 mile semi long runs usually with hills (i live in boston so i just do the heartbreak hills and run back into town)
friday: rest
saturday: 4-6 mile runs at 5k, 10k or marathon pace
sunday: long runs with the really long runs every other week.
with this schedule, i think i'm hitting all the different workouts that you mentioned (tempo, long, etc.). i'll give the 800 repeats a try for this marathon and see if my 2nd marathon time is around 3:45:00. for my first marathon, my goal was surviving. from here on in, i'd like to improve on my times and in 2-3 years qualify for boston instead of going the charity route. i guess we'll see what happens.
thanks for the advice though.