How to run a faster marathon?

I improved in 2007/8 season from 3.20hr to 3.00hr on the marathon, 1.27.30 on HM, and 38.20 on 10K. Especially on the FM I now wonder how to improve my training to reach a 2.50-2.55? I had a nice rest since my last marathon and am now fired up to go again. My previous marathon regime consisted of (1) peaks of up to 85K per week, (2) 4-5x running mostly easy, (3) at least 5 long runs per cycle between 32-36K, (4) weekly tempos up to 40min at ~15K pace, (5) one hill session a week in first 2/3 of cycle, (6) one interval session a week in last 1/3 of cycle, and (7) very limited leg-strength training in gym. What is the way to get faster? Or just continue what I am doing... Increase mileage to 90-100K peaks? More pace or tempo work, and if so in what form as my focus is marathoning? More strength training in hills or gym? Let me know what you do to get faster, as there are some very experienced runners out there in HK! Ok, and let's ignore the summer heat broadly as my next marathon is in November.